If you have modeless form, then you can use something like:

wait wind trans(type("yourformname")="O" and not isnull(yourformname))

otherwise you need to call the form like:
do form yourformname NAME yourformname
to use the code above.

>How can I check and see if a form is running (the form that I'm checking for (from another form) has enabled set to .F. and is not visible.