>How to know if a form is activated before.

If you know what the forms object reference would be, you could do soemthing like what Barabra said testing the variables type and that its not null. If you know the name of the form and not just the SCX, you can do what Nick suggests.

The best way to handle this though is with a Form Manager. WHen that keeps an array around of all the current forms, including the SCX name, then you can easily and safely tell if its open or not.