Linked Lists

//Jeff Letendre				
#include <stdlib.h>						//for malloc()
#include <stdio.h>						//for printf(), scanf(), fflush()
void main (void);				  		///////////////////////////////////////
struct node * merge (struct node *, struct node *);	   	///////////////////////////////////////
struct node * reverse (struct node **);				///////////////////////////////////////
struct node * createList (void);				///////////////////////////////////////
struct node * subtract (struct node *, struct node *);	  	///////////////////////////////////////
struct node * addSort(int, struct node **);			///////////////////////////////////////
struct node * getMemory(void);					///////////////////////////////////////
struct node * InsertAfter (struct node **);			////////////// prototype //////////////		
struct node * intersection (struct node *, struct node *); 	////////////// section ////////////// 
struct node * search (int, struct node *);			///////////////////////////////////////
struct node * bubbleSort (struct node *);          	///////////////////////////////////////
void PrintList (struct node *);					///////////////////////////////////////
void deleteNode (struct node **);				///////////////////////////////////////
void free_node (struct node **);				///////////////////////////////////////
int palindrome (struct node *plist);				///////////////////////////////////////
void errorExit (char *);					///////////////////////////////////////
struct node							//structure template
  {
  struct node *previous;					//pointer to previous node in list
  int data;							//integer list data 
  struct node *next;						//pointer to next node in the list
  };
////////////END OF HEADER SECTION////////////////

void main (void)
  {
  struct node *plist = NULL;				 	//pointer for first list
  struct node *plist2 = NULL;					//pointer for second list 
  struct node *pnode = NULL;			  		//pointer for node
  struct node *tempList = NULL;          		//misc. pointer for returned lists 
  int option = 0, choice = 0;           		//variables for user input
	 
  while (true)							//main program loop set to infinite loop
   {
   printf("\n\nPlease make a selection:\n\n");		//prompt for input
   printf(" 0 = Add in sorted order\n");
   printf(" 1 = Create a list\n");
   printf(" 2 = Seek and destroy\n");
   printf(" 3 = Exit\n");
   printf(" 4 = Search\n");
   printf(" 5 = Intersection\n");
   printf(" 6 = Print\n");
   printf(" 7 = Merge two lists\n");
   printf(" 8 = Create another list\n");
   printf(" 9 = Palindrome?\n");
   printf("10 = Reverse list \n");
   printf("11 = Subtract two lists\n");
   printf("12 = Insert after\n");
   fflush(stdin);						//clear input buffer
   scanf("%d", &option);            		//scan new option
   switch(option)		
     {	
     case 0:
	  {
	  printf("Enter an integer to be added to the list or -99999\n");
      scanf("%d", &choice);
	  while (choice != -99999)			   	//call addSort
        {
	    plist = addSort(choice, &plist);
	    printf("Enter another integer or -99999 to quit\n");
	    fflush(stdin);
	    scanf ("%d", &choice);
	    }
      break;
      } 
     case 1:
 	  {
      plist = createList();
	  break;
 	  }
     case 2:
	  {
	  deleteNode(&plist);	//no return modifying original list
 	  break;
	  }
     case 3:
 	  {			 
	  exit(1);
 	  break;
 	  }
     case 4:
	  {
	  printf("Enter a value to search the list for:\n");
	  scanf("%d", &choice);
      tempList = search(choice, plist);
      if (tempList == NULL)
        {
        printf("The value %d was not found in the list\n", choice);
        break;
        }
	  else 
        {
        if(tempList->previous == NULL && tempList->next == NULL)
         printf("%d is the only value in the list\n", tempList->data);
        else if(tempList->previous == NULL && tempList->next != NULL)
         printf("%d is the first value in the list followed by %d\n",
           tempList->data, (tempList->next)->data);
        else if(tempList->previous != NULL && tempList->next == NULL)
         printf("%d comes after %d and is the last value in the list\n",
           tempList->data, (tempList->previous)->data);
        else if(tempList->previous != NULL && tempList->next != NULL)
         printf("%d comes after %d and before %dlist\n", tempList->data,
           (tempList->previous)->data, (tempList->next)->data);
        break;
        }
	  }  
     case 5:
	  {
      tempList = intersection (plist, plist2);
      if(tempList != NULL)
        {
        tempList = bubbleSort(tempList);
        PrintList(tempList);
        }
	  break;
	  }
     case 6:
	  {
	  PrintList(plist);
	  break;
	  }
     case 7:
      {
   	  tempList = merge (plist, plist2);
      PrintList(tempList);
	  break;
	  }
     case 8:
	  {
	  plist2 = createList();
	  break;
	  }
     case 9:
	  {
	  if(palindrome(plist))				   //if palindrome returns 1
	    {
	    PrintList(plist);
	    printf(" it is a palindrome.\n");
	    }
	  else
        {
	    PrintList(plist);				     //else list is not a palindrome
	    printf(" it is not a palindrome.\n");
	    }
	  break;
	  }
     case 10:
	  {
      PrintList(plist);           //print list before reversing
      printf("\n\nReversing...\n\n");
	  plist = reverse(&plist);			   //call to reverse func 
      PrintList(plist);           //print reversed list      
	  break;
	  }
     case 11:
	  {
	  printf("How shall I subtract your lists?\n"); 
      printf("1 = First list entered minus second list entered or\n");
      printf("2 = Second list entered minus first list entered?\n");
      scanf("%d", &choice);
	  if (choice == 1)
        {
        tempList = subtract (plist, plist2);
        }
      else if (choice == 2)
        {
        tempList = subtract (plist2, plist);
        }
      else
        {
        printf("Incorrect choice escaping to main menu\n");
        break;
        }
      PrintList(tempList);
      break;
	  }
     case 12:
	  {
	  plist = InsertAfter(&plist);	//Insert After has capability to
	  break;               //start a new list if plist is empty
	  }
     default:
	  {
	  printf("Your only options are zero (0) through eleven (11)\n");
	  printf("Enter new option\n\n");
	  break;
	  } 
     }  //end switch    
   }  //end while
  }//////////////end main()/////////////////
struct node * addSort(int newVal, struct node **plist)
  {
  struct node *newNode;
  struct node *ptemp;
  ptemp = *plist;
  newNode = getMemory();			//call getMemory to allocate and test
  newNode->data = newVal;			//copy int into struct
  while(ptemp != NULL && ptemp->data <= newNode->data && ptemp->next != NULL)
   ptemp = ptemp->next;
  if(ptemp == NULL)				//if list is empty
   {
   newNode->next = NULL;			//set next to NULL
   newNode->previous = NULL;		   	//set previous to NULL
   *plist = newNode;				//set list pointer to newNode
   }
  else if(ptemp->previous == NULL && ptemp->data > newNode->data)//at begining of list
   {
   newNode->previous = ptemp->previous;
   newNode->next = ptemp;
   ptemp->previous = newNode;
   *plist = newNode;
   }
  else if(ptemp->next == NULL)		 	//at end of list
   {
   newNode->previous = ptemp;
   newNode->next = ptemp->next;
   ptemp->next = newNode;
   }
  else if(ptemp->data > newNode->data)		//inbetween begining and end of list 
   {
   newNode->next = ptemp;
   newNode->previous = ptemp->previous;
   (ptemp->previous)->next = newNode;
   ptemp->previous = newNode;
   } 
  return(*plist);				//pass back list pointer
  }	////////////end add sort//////////////////

struct node * bubbleSort (struct node *listHead)//sorts a doubly linked list of ints
  {                      //returns pointer to sorted list
  struct node * listp1 = NULL;
  struct node * listp2 = NULL;
  listp1 = listHead;              //assign pointer to list head
  listp2 = listHead->next;           //assign pointer to next node
  while(listp1 != NULL && listp2 != NULL)
   {
   if(listp1->data <= listp2->data)     //if in ascending order w/ next node
     {
     listp2 = listp2->next;         //skip to next 2 nodes
     listp1 = listp1->next;
     }
   else                   //else swap order
     {
     listp1->next = listp2->next;
     listp2->previous = listp1->previous;
     if(listp1->previous != NULL)      //if not the first node
      (listp1->previous)->next = listp2; //point previous node's next field to listp2
     listp1->previous = listp2;
     if(listp2->next != NULL)        //if there is a next node
      (listp2->next)->previous = listp1; //point its previous field to listp1
     listp2->next = listp1;
     if(listp1 == listHead)         //reset pointers to begining of
      listHead = listp2;
     listp1 = listHead;
     listp2 = listp1->next;
     }
   }  //end while
  return listHead;
  }///////////////////end bubbleSort///////////////////////

struct node * createList(void)
  {
  struct node * plist = NULL;			//pointer for new list
  struct node * temp = NULL;			//pointer for inserting into list
  struct node * pinsert = NULL;		//pointer for node allocation
  pinsert = getMemory();			//call getMemory to allocate and test
  pinsert->next = NULL;			//set node pointers to NULL
  pinsert->previous = NULL;		
  plist = pinsert;				//point list pointer to first node
  printf("Type a list of integers to be created\n");
  printf("Enter -99999 to finish input cycle\n");
  printf("Enter first integer for new list\n");
  scanf("%d", &(pinsert->data));	  	//scan new value
  while (pinsert->data != -99999)
   {	
   temp = pinsert;
   pinsert = getMemory();			//call getMemory to allocate and test
   pinsert->next = NULL;			//copy NULL to new node's next field
   pinsert->previous = temp;
   temp->next = pinsert;
   printf("Enter an integer to be added after %d:\n", temp->data);
   scanf("%d", &(pinsert->data));		//scan into struct's data element value
   }
  fflush(stdin);
  free(pinsert);				//free node which contains sentinel (-99999)
  temp->next = NULL;              //assign last node's next pointer to NULL
  return (plist);				//returns NULL if list contains sentinel only
  } //////////////End createList/////////////

void deleteNode (struct node ** plist)     //deletes node from list
  {
  struct node *temp = NULL;
  struct node *next1 = NULL;
  int delVal = 0;
  next1 = *plist;				//set pointer to list head
  printf("Enter a value and I will delete all nodes\n");
  printf("whose data element matches your value\n");
  scanf("%d", &delVal);	
  while(next1 != NULL)				//search through whole list
   {
   if(next1->data == delVal)			//if delVal is found
     {
	 if(next1->next == NULL && next1->previous == NULL)	//if deleting only node
	  {				   	//deleting only node. Point plist to NULL
	  free(next1);				
	  *plist = NULL;
	  }
	 else if(next1->previous == NULL)	//if deleting first node
      {
	  next1 = next1->next;		//skip next1 to next node
	  next1->previous = NULL;		//since first node assign previous to NULL
	  *plist = next1;			//point the list pointer to the new first node
      free(temp);				//free old first node
 	  temp = *plist;			//point temp to list
	  }
     else if(next1->next == NULL)		//if deleting last node
      {
	  temp->next = NULL;			//set temp as last node
	  free(next1);			//free last node in list
	  next1 = temp->next;			//point next1 to NULL;
	  }                  //end else
     else                  //else deleting a node between nodes
      {
	  temp->next = next1->next;		//shift pointer to skip over node to be deleted
	  (next1->next)->previous = temp;	//point previous element of 1st node after deleted node to temp
	  free(next1);			//free node
	  next1 = temp->next;			//point next1 to next node
      }  //end else
     }  //end if
   else
     {
	 temp = next1;
	 next1 = next1->next;			//go through list
	 }                   //end else
   }                   	//end while
  }////////////////end deleteNode()///////////////

void errorExit(char *string)          //prints error & exits program
  {
  printf("%s", &string);
  exit(1);
  }/////////////end errorExit()///////////////

void free_node (struct node **pnode)
  {
  struct node *ptemp;				//temp pointer used for swaping structure pointers
  if(pnode == NULL)				//if list is empty
   errorExit("Attempt to delete from a NULL node pointer");
  ptemp == (*pnode)->previous;		   	//point to previous node
  ptemp->next = (*pnode)->next;		//mend break in links
  free(pnode);					//release memory back to OS
  }/////////end free_node/////////

struct node * getMemory(void)          //allocates & tests return value 
  {
  struct node * newPtr = NULL;
  if((newPtr = (struct node *) malloc(sizeof(struct node))) == NULL)
   {  					//if malloc returns a NULL pointer
   printf("ERROR! Unable to allocate memory - Abort\n");
   abort();					//print error msg & abort function
   return(0);				//make the compiler happy :>)
   } 
  else 
   return newPtr;
  }   ///////////////////end getMemory///////////////

struct node * InsertAfter(struct node **plist)
  {
  struct node *tempNode;
  struct node *tempList;
  int afterVal = 0, choice = 0;
  tempList = *plist;
  tempNode = getMemory();			//call getMemory to allocate and test
  if (tempList == NULL)			//if list is empty
   {
   printf("Your list is empty. Should I create a list for you?\n");
   printf("1 = Yes\n2 = No\n");
   scanf("%d", &choice);
   if(choice == 1)
     {
     printf("Enter an integer\n");     //prompt and get input
     while(scanf("%d", &choice) < 1)    //testing scanf//reusing choice for data input
      printf("Incorrect value entered. Please try again:\n");   
     tempNode->data = choice;    
     tempNode->previous = NULL;       //set pointers
     tempNode->next = NULL;
     }
   else if(choice == 2)           //if user doesn't want to create list
     tempNode = NULL;            //set return pointer to NULL
   return tempNode;             //return pointer
   }  //end if
  else                 	//list is not empty
   {											     
   printf("Enter an integer to insert the next node after\n");
   scanf("%d", &afterVal);				//assign new value to data field
   for(; tempList != NULL && tempList->data != afterVal; tempList = tempList->next);
     if (tempList == NULL)
      {
      printf("Error list value not found\n");	//print error msg.
      return(tempList);				//return NULL pointer
	  }
	 else if(tempList->data == afterVal)
      {
	  printf("Enter an integer to be added after %d\n", tempList->data);
	  scanf("%d", &(tempNode->data));		//get new data value
	  tempNode->next = tempList->next;		//assign new node's next field to plist's next field
	  tempList->next = tempNode;		  	//copy temp into plist's next field
	  tempNode->previous = tempList;		//copy plist to temp's previous field
      }
	  }  //end else
	return (*plist);
  }///////////End InsertAfter////////////

struct node * intersection (struct node *opList1, struct node *opList2)
  {
  struct node *temp = NULL;
  struct node *intList = NULL;
  
  temp = getMemory();
  intList = temp;               	//list head pointer
  if(opList1 == NULL || opList2 == NULL)
   {
   printf("Empty list(s) - can not take intersection\n");
   temp = NULL;
   return temp;
   }
  while (opList1 != NULL)
   {
   if(search(opList1->data, opList2) != NULL)  
     {                   	//if data is not in list
     temp->previous = opList1->previous;  	//copy node into new list
	 temp->data = opList1->data;
	 temp->next = getMemory();       	//allocate more memory
     (temp->next)->previous = temp;     	//point next nodes previous field to current node     
     temp = temp->next;           	//point temp to next node
     opList1 = opList1->next;
     }  //end if
   else
     opList1 = opList1->next;
   }  //end while
  (temp->previous)->next = NULL;        	//terminate links w/ NULL
  free(temp);                 	//release extra node back to OS
  return intList;
  } /////////////end intersection////////////////

struct node * merge (struct node *listA, struct node *listB)
  {
  struct node * listHead = NULL;      		//pointer to new merged list
  listHead = listA;              		//set pointers to begining of listA
  while (listA->next != NULL)        		//skip to end of listA
   listA = listA->next;  
  listB->previous = listA;       		//append listA with listB
  listA->next = listB;
  listHead = bubbleSort(listHead);       	//sort new list
  return listHead;               	//return pointer to new merged sorted list
  } ////////////end merge//////////////////

int palindrome (struct node *plist)	
  {
  struct node *temp1;
  struct node *temp2;
  int i = 0, j = 0;
  
  temp1 = temp2 = plist;					//set both temp vars to the list pointer
  for (i=0; temp2->next != NULL; temp2 = temp2->next, i++);	//terminated for loop to move to end of list
   for(j = 0; j < i; j++)
     {
     if (temp1->data != temp2->data)			//if values not equal
 	  return (0);									
	 else
      {
	  temp1 = temp1->next;				//increment temp1
	  temp2 = temp2->previous;				//decrement temp2
      }
     }  //end for loop
  return(1);
  } ///////////end palendrome///////////////

void PrintList (struct node *plist)
  {
  int i = 0;
  if(plist != NULL)
   {
   printf("Here is your list:");	
   while (plist != NULL)
     {
	 if((i % 10) == 0)		       	//CRLF first line then print ten values per line
	 printf("\n");
	 printf("--> %d ", plist->data);
	 plist = plist->next;	         	//point plist to next node
	 i++;
	 }  //end while loop
   }  //end else statement
  } ///////////////end PrintList()////////////////

struct node * reverse (struct node ** plist)
  {
  struct node *rList = NULL;
  struct node *ptemp = NULL;
  struct node *pt2 = NULL;
  
  ptemp = *plist;
  while(ptemp->next != NULL)
   {
   ptemp = ptemp->next;		    		//point ptemp to end of list
   }
  rList = ptemp;
  *plist = rList;				  	//set list pointer to end of list
  while(ptemp != NULL)
   {
   ptemp = ptemp->previous;
   rList->previous = rList->next;
   rList->next = ptemp;
   rList = ptemp;
   }
  return(*plist);
  } //////////end reverse////////////////////

struct node * search (int data, struct node *pstack)	
  {
  struct node *ptemp;
  for (ptemp=pstack; ptemp != NULL && ptemp->data != data; ptemp = ptemp->next);
  return ptemp;                	//returns NULL if data not found
  }///////////end of search///////////////

struct node * subtract (struct node *opList1, struct node *opList2)
  {
  struct node *temp = NULL;
  struct node *subList = NULL;
  
  temp = getMemory();
  subList = temp;               	//list head pointer
  while (opList1 != NULL)
   {
   if(search(opList1->data, opList2) == NULL)  
     {                   	//if data is not in list
     temp->previous = opList1->previous;  	//copy node into new list
	 temp->data = opList1->data;
	 temp->next = getMemory();       	//allocate more memory
     (temp->next)->previous = temp;     	//point next nodes previous field to current node     
     temp = temp->next;           	//point temp to next node
	 opList1 = opList1->next;
     }                   	//end if
   else
     opList1 = opList1->next;
   }                     	//end while
  (temp->previous)->next = NULL;        	//terminate links w/ NULL
  free(temp);                 	//release extra node back to OS
  return subList;
  }//////////end subtract////////////////
/////////////////////////////////// END PROGRAM /////////////////////////////

function mstrGetRelativeURL()
	
	mstrGetRelativeURL=Request.serverVariables("PATH_INFO")
	
end function
Upload
<?php
// $Id: authticket.phl,v 1.3 1998/02/11 16:45:34 explorer Exp $
//
// Copyright (c) 1998 Michael Graff <explorer@flame.org>
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//  notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
// 3. Neither the name of author nor the names of its contributors may be
//  used to endorse or promote products derived from this software
//  without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
class authticket {
	var $secret = "setme";		// you WILL want to change this
	var $realm = "";		// the realm of this identity
	var $lifetime = 2 * 60 *60;	// tickets good for 2 hours
	var $authenticated = 0;		// the data here is valid iff non-zero
	var $identity;		// the remote identity, if decoded correctly
	var $issue;		// the time the ticket was issued
	var $remote_addr;	// the remote address of the client
	var $hash;		// the hash value. Probably of little use.
	var $autherr;		// if verification faild, this contains why
	//
	// helper function which just zeros out the ticket data
	//
	function zerodata()
	{
		$this->authenticated = 0;
		$this->identity = "";
		$this->issue = 0;
		$this->remote_addr = "";
		$this->hash = "";
		$this->autherr = "";
	}
	//
	// Take a string ($identity) and a time ($time) and the internal
	// secret value, and generate a string that can be used to verify
	// that the remote user is known to us. The result of this function
	// is a single string, that can be passed along in a hidden form
	// or even a cookie.
	//
	// If ($time) is 0, the current time is used instead.
	//
	// ($identity) _cannot_ contain a ``:'' character. If you need
	// one in there, you will have to change it to some sort of escape
	// sequence.
	//
	// Some care should be used. I recommend using this only over SSL,
	// unless the actual ticket contents are encrypted using something
	// stronger than XOR.
	//
	function makeauth($identity, $time)
	{
		global $REMOTE_ADDR;
		$this->zerodata();
		if ($time == 0)
			$time = time();
		$ticket_items[] = (string)$time;
		$ticket_items[] = $this->realm;
		$ticket_items[] = $REMOTE_ADDR;
		$ticket_items[] = $identity;
		$ticket = implode($ticket_items, ":");
		$hash = md5($this->secret . $ticket);
		$ticket = $hash . ':' . $ticket;
		$this->identity = $identity;
		$this->issue = $time;
		$this->remote_addr = $REMOTE_ADDR;
		$this->hash = $hash;
		$this->authenticated = 1; /* data is valid */
		$this->autherr = "";
		return $ticket;
	}
	//
	// Take a ($ticket) string generated by makeauth(), and a ($time),
	// and verify that the ticket is valid and not expired.
	//
	// If ($time) is 0, the current time will be used.
	//
	// On error, the function returns the empty string "",
	// $authenticated is 0, and $autherr contains the reason
	// the authentication failed.
	//
	// On success, the identity encoded in the ticket is returned,
	// $authenticated is non-zero, and $autherr is to be ignored.
	//
	function checkauth($ticket, $time)
	{
		global $REMOTE_ADDR;
		$this->zerodata();
		if ($time == 0)
			$time = time();
		/*
		 * Item order: hash time realm remote_addr identity
		 */
		$ticket_items = explode(":", $ticket);
		/*
		 * if the remote address doesn't match the one in the ticket,
		 * drop them.
		 */
		if ($ticket_items[3] != $REMOTE_ADDR) {
			$this->autherr = "Address mismatch";
			return "";
		}
		//
		// if we are supposed to check for expired tickets, do that
		// here.
		//
		if ($this->lifetime != 0)
			if ($time > (int)$ticket_items[1] + $this->lifetime) {
				$this->autherr = "Ticket expired";
				return "";
			}
		//
		// make certain that the ticket is not being used before
		// it was issued.
		//
		if ($time < (int)$ticket_items[1]) {
			$this->autherr = "Ticket used before issued";
			return "";
		}
		//
		// verify that the realms match
		//
		if ($this->realm != $ticket_items[2]) {
			$this->autherr = "Realm mismatch";
			return "";
		}
		//
		// This could be done better... Reassemble the components
		// of the ticket passed to us, and rehash. Compare this
		// to the hash we were sent.
		//
		$tmp_items[] = $ticket_items[1];
		$tmp_items[] = $ticket_items[2];
		$tmp_items[] = $ticket_items[3];
		$tmp_items[] = $ticket_items[4];
		$tmp_ticket = implode($tmp_items, ":");
		$hash = md5($this->secret . $tmp_ticket);
		if ($hash != $ticket_items[0]) {
			$this->autherr = "Integrity check failed";
			return "";
		}
		//
		// well, it all checks out. Might as well claim we know
		// who this person is.
		//
		$this->hash = $hash;
		$this->issue = $ticket_items[1];
		$this->remote_addr = $ticket_items[3];
		$this->identity = $ticket_items[4];
		$this->authenticated = 1;
		return $this->identity;
	}
};
?>

DropDownList.SelectedIndex = DropDownList.Items.IndexOf(New ListItem("ABC"))
or
DropDownList.SelectedItem.Text = "ABC"