Testing, if form exists
Sometimes a form may be launched from several places in a program. If it already exists, it only needs to be brought to the front. If not, it needs to be created.
This method is only needed if the form is not auto created. (It will be listed under Project|Project Options|Forms|Available forms.)
The easiest way is:
if MyForm <> nil then MyForm.Show else begin MyForm := TMyForm.Create(Application); MyForm.Show; end;
Use CloseAction := caFree in the form's OnClose event.
This method is taken from forum discussions.