C# ASP.NET Calculate Age based on date of birth

Question

I have 2 textboxes , txtDOB and txtAge

 

I am using jquery datepicker to get the date in txtDOB (date of birth textbox)

What i want is when i select date of birth from datepicker in my date of birth textbox i.e txtDOB

I want the age to be calculated automatically On age textbox i.e txtAge

I searched on internet but i am not finding the perfect one. I am stuck so far i have not done any coding to calculate age based on DOB.

Any help or any suggestion will be much appreciated

Thanks