Showing Forms

How would I go about doing this: I need to show two different forms one after another. For example; a menu screen (1st screen) with a command button that will pop up another screen (2nd screen) for the user to enter details about themselves. After clicking on the command button (On the 1st screen) that screen to would hide but be brought back if they click cancel. (It's a bit like having a cancel button but it goes back to the main screen instead of closing the form.) Cheers