Remove TextBox Popup

This code does some useful things. First ,it replaces the default textbox context menu(the menu which pops up when u right click the textbox or press context menu key on the keyboard) with menu of ur choice. Secondly it shows how u can create ur own Edit Menu. Thirdly it shows how u can restrict user from pasting into textbox(it may be desired in some cases). Users can't paste into textbox by any means.I found some codes on the site where u could replace the textbox default popup menu but all failed when user pressed context menu key/application key on keyboard(the key immediate to Right Windows Key). I hope u find it of some use ;-).