Accessing Gridview Template fields

Question

Hi there,

            I need C# code to access a textbox inside a gridview template field i want to insert a string manually into it
what i did:
  I editted the columns and inserted template fields and editted template field and inserted a textbox now my prob is i want to access that textbox i.e i wanna insert a string into it so that on the page load event i can view the gridview with the textbox init and the string inserted init

please help

regards
Naveen...