how to check if all textbox in windows form is empty

Question

Hii

I am new to c#.net.
I have one application in which i have 100 textbox.
if user clicks cancel button i want to show a  message that "data you have entered  will lost"..

So how can i check if all textbox in a form is empty or not.

Please help me in this problem..'

Thanks in advance

Rahul Patel