clean way for telling if a form is present

i have an appl with 2 forms firstform and form1. first form is the startup form. sometimes it shows form1. when i close firstform in its form closing event i want to know if form1 is present as i want to save the data of form1 that i may have changed when form1 was shown but was of course not changed if form1 was not shown.

thank you

follys