Can I edit excel 2003 templates?

[ericgreen]

Ok so I have excel 2003, I opened a template that it came with called "sales invoice". Now if I want to edit certain cells, it wont let me. It comes up with these yellow tip boxes with a message in them saying something like "you can put the sales tax here" but I want to enter formulas and stuff but it wont let me edit the cells. I am guessing this is because its a template....but is there anyway to totally unlock the template for more editing and customization? Thanks

[Paul]

I opened that same Sales Invoice template, and all I had to do to start editing it was go to Tools > Protection > Unprotect Sheet. There is no password on the sheet.