Un-Spliting excel work-sheet
 

I was working on a spreadsheet in Excel when I accidently hit the "split"
icon without realizing it until I entered a couple additional entries. On my
"View" tab, the undo was grayed out and when I tried to do something in the
"split" mood, I just made one big mess. The on-screen help was absolutely NO
help at all (and usually isn't). It just told me to go to the "window"
drop-down menu, which doesn't appear in 2007. I finally just closed the
program without saving (which lost of course what I did enter before I split
the screen...and had to just start over.) Very frustrating.
So how does one correct a split screen if the undo is grayed out?

Thank you for any assistance on this issue.