I want to catch an exception when user enter no value in a Textbox and try to process further by press a button, I know I can use "If else" statement to make it. but in terms of "Try and Catch" block, I dont know how. Here is the code sample. Dim NameString As String Try NameString = OperatorNameTextBox.Text Catch ex As ArgumentException MessageBox.Show("Enter a String Value") End Try