Handling Null Request variables in VB.Net

By approaching below code,we can avoid Request variables null values.

Make shared function as below:

Public Shared Function Check_Request_Variables_Null_Value(ByVal request_variables As HttpRequest,ByVal key_item As String) As String

   Dim result As String = string.empty

   if request_variables(key_item) <> Nothing Then
      result = request_variables(key_item)
   End If

   Return result

End Function