How do I make my Excel 2003 document work in Excel 2000?

I created an Excel spreadsheet in 2003 and later found out that the users of
the spreadsheet only have Excel 2000 and are unable to enter data on the
spreadsheet.

How can I make this spreadsheet functionable to the 2000 users??

Thank you for any help you can give.

When you save your document with the option "Save as", you will find a
listbox where you'll find the option 'Microsoft Excel 97-2000 & ...".
Ofcourse when you save the document in this version you have to Recheck
everything because it's possible that some of the things you
programmed/implemented do not work, work half or just don't exist
anymore in that version... then you'll have to re-invent (the wheel ?
;-) )

Bye
Baj