FTP Form

I'm looking for a simple form (see attached)that generates a text file that's FTPed to a specific location. So, When I select Studio A and click submit it would generate a file called studioa.txt. When I click Studio B and click submit it would generate a file called [login to view URL] and when I click Studio C it would generate a file called studioc.txt. When I select the "turn off" check box and click submit it would generate a file called turnoff.txt. Now for the hard part. I only want one file in a directory at a time. So, if I click Stuio A and create [login to view URL] then select Studio B, I'd want it to erase [login to view URL] and replace it with studiob.txt. Likewise, if I choose "turn off" I'd want it to erase [login to view URL] and replace it with turnoff.txt. Finally, I wouldn't want you to be able to select a menu item from the drop down menu if the "turn off" button has been selected.