I am trying to design a simple excel spreadsheet that will calculate overtime
worked. I want it to display similar to this. The spreadsheet would
hopefully be a template and password protected, so all one would have to do
is fill in the blanks.

Sunday 13:30 17:30 4
Monday 17:00 18:00 1
Tuesday 17:00 17:30 .5
etc
TOTAL 5.5

Any suggestions, as I am stymied on how to do this. I am using Excel 2003.
Thanks.