Function	BoxYesNoCancel( Question: String ): Integer
Description
Displays an Isah dialog box containing the following buttons: Yes, No and Cancel.
Remarks
The default button is Yes. For more information on possible return values, please refer to IsahForms Object.
Example
  Sub Main()
    If Proceed("Do you want to process the remainder") then
    MsgBox "OK"
    End If
  End Sub
  Function Proceed( ProceedStr )
  Proceed = (Application.IsahForms.BoxYesNoCancel( ProceedStr ) = 6)
  End Function