[AccessD] OT: Excel

Dear List:
 
Sorry for the OT but I'm in Excel and hit something, some control key or
alt-something, who knows? and now when I use the arrow keys the sheet moves
instead of the cell with the focus moving.  
 
Can't figure out from the menus where this particular switch is.  Nothing I
put in Help seems to tell me.
 
WHAT HAVE I DONE??!!  Better yet, how do I undo it.
 
MMTIA,
 
Rocky