Prob In Time Duration ?

Question

Hai, Frnds,

               I have problem to find the exact time duration . Like this ---> I have {From time} and {To time} two fields in table in SQL server 2008 database. In this how should i find exact duration of this Time....? ? ? 

Table:

--------

From Time         To Time                Duration 

01:05:10 Pm    02:05:10 Pm          01:00:00 

Thanks In Advance :)