How calculate total time for two different times in c#

Question

Hai,

 

Here I want to calculate total time of two different time .Here I can enter the starting date and starting time and after finished that work i can enter the end date and end time . 

 

How can I find the Total time for  these two  dates and times in c# windows application.

 

Please anybody give me an idea to solve this problem . Thanks in advance.

 

ex.
 

Start Date	Start Time	End Date	End Time	Total Time
01-12-2015	09.00 AM	03-12-2015	10.00 PM	Answer???