>This works as expected
>
>DEFINE CLASS ywmp AS form
>
>
>When I try to do the following
>
>DEFINE CLASS ywmp AS ultx_AutoCenteredTopForm OF ultxbase
>
>I receive a compilation error telling me "Unable to find Program ultxbase"
>
>How should I do it?

Do you have a classlib (vcx) called ultxbase.vcx?
And does it contain a form class called ultx_AutoCenteredTopForm?