Top of spreadsheet hidden under toolbars

I have a user that has Office 97. She has an Excel spreadsheet that somehow she has managed to get the top of the spreadsheet under the toolbars.
If you scroll all the way up on the spreadsheet the row with the column headings (A,B,C,etc) will notshow. It is only effecting this one spreadsheet and not the others.
Thanks
Edie Dudley