I am trying to create a spreadsheet to calculate hours worked. I need to know
what formulas to use to calculate the time in hours and overtime hours. for
example:

A1= 6:00 am start time
B1= 11:15 am start lunch
C1= 11:45 am end lunch
D1= 17:00 pm end time

I need E1 to reflect total hours worked to a maximum of 10 hours/day and I
need F1 to reflect overtime time hours in excess of 10 hours/day.

E1= 10.00 regular hours worked
F1= 00.50 overtime hours worked

PLEASE HELP!