Group By date calculation question

My server has MySQL 4.1 and I have a table that has employee name, time in and time out.

employee:timein :timeout
0001 :2006-07-01 21:00 :2006-07-02 05:00
0001 :2006-07-02 21:00 :2006-07-03 05:00
0002 :2006-07-01 21:00 :2006-07-02 05:00
0002 :2006-07-02 21:00 :2006-07-03 05:00
0003 :2006-07-01 21:00 :2006-07-02 05:00
0003 :2006-07-02 21:00 :2006-07-03 05:00

I am trying to get it to calculate the total hours for each employee.

employee:hours
0001 :16
0002 :16
0003 :16


Any help would be greatly appreiciated!