How to determine the number of hours and minutes between a start time and an end time

[kkundra]

Hopefully everyone can see the two sample attachments which are the same thing just different extensions (PDF, and JPEG).

Basically I'm trying to make a very simple weekly time sheet where I enter the time in and time out, and it calculates the number of hours. Simple concept. The problem is how Excel forces two formats, neither of which I want. It either does h:mm AM/PM or 24 hour time. I simply want it displayed like in the attachments AND I would like it entered that way.

I played around with different cell formats but nothing seems to work like it want. Because the first row is "assumed" to be AM and the second row is "assumed" to be PM, I want the speed and efficiency of just typing in hh:mm on a 12 hour system.

Please help....simple but frustrating.