Time Calculation problem

I've attached a sample of what I'm trying to accomplish, but I can't seem to get the correct answer. I have a start time, an end time and I want a total hours worked or rather time column as well. I've researched on this site for similar questions and have implemented what I thought would work. i.e; =MOD(e4-d4,1), but it doesn't seem to be giving me the answer I'm looking for. Anyone have any suggestions how I might be able to fix this problem.

Thanks in advance!