Rick,

>When I go to test the business rules by invoking a method, I receive the Invoke Method window. I enter a string "G123", this error:
>
>An unhandled exception of type 'System.InvalidOperationException' occurred in Microsoft.VisualBasic.dll
>
>Additional information: The ConnectionString property has not been initialized.

Did you remember to instantiate an instance of AAppTest first?

Best Regards,