ASP.NET Popup Windows

Public Function BuildPopUpScript(ByVal Page As String, _
                    Optional ByVal dialogWidth As Int32 = 255, _
                    Optional ByVal dialogHeight As Int32 = 255, _
                    Optional ByVal modal As Boolean = True) As String
    Try
      Dim jsmodal As String
      If modal Then
        jsmodal &= "if (window.showModalDialog)"
        jsmodal &= "{window.showModalDialog('" & Page.Trim & "','name',"
        jsmodal &= "'dialogWidth:" & dialogWidth & "px;dialogHeight:" & dialogHeight & "px;status:no;help:no;scroll:no');}"
        jsmodal &= "else{"
        jsmodal &= "window.open('" & Page.Trim & "','name','height=" & dialogHeight & ","
        jsmodal &= "width=" & dialogWidth & ",toolbar=no,directories=no,status=no,"
        jsmodal &= "menubar=no,scrollbars=no,resizable=no,modal=yes');"
        jsmodal &= "}"
      Else
        jsmodal &= "window.open('" & Page.Trim & "','name','height=" & dialogHeight & ","
        jsmodal &= "width=" & dialogWidth & ",toolbar=no,directories=no,status=no,"
        jsmodal &= "menubar=no,scrollbars=no,resizable=no,modal=no');"
      End If
      Return jsmodal
    Catch ex As Exception
      Return "alert(" & ex.Message & ");"
    End Try
  End Function