If you are closing the form2 (trough command like thisform.release() or any other way), so you can't call the form2 again because it was released from memory.

If this is the case, put the following code on queryunload event on form2:

thisform.hide()
nodefault

This code will not allow you to release the form2, so this form is always in memory and can be called when you need it. But, remember that you must release it when you release the form1, calling: thisformset.form2.release()