select all checkboxes in multiple gridview with same button

Question

Hi frnd
thanx for the solution, but i have one more problem i will expalin the scenario
i have 3 radiobuttons and 3 griviews and one button to select all the checkboxes in the gridview.k
if i select 1st radiobutton then iam able to select all the checkboxes in the gridview,
but if  i iam selecting the second radiobutton then how to select all the checkboxes
and  if i select 3rd radiobutton then how to select the checkbox in the grid view
can u please help me