Pass value of label text to URL in Web Form

Hello,
I know this must be easy, and I KNOW I have done this in the past, but I cannot for the life of me remember how to do this...
I want to take the text of three labels OR values of three variables in my .cs file and pass them as values in a URL in my web form.
Example:
"http://www.example.com?fname=" + lblfname.text + "&lname=" + lbllname.Text + "&email=" + lblemail.Text;
How can I do this?
Cheers,
~D