Hiding gridview columns on page load

I've added this to the code behind:

'Private Sub GridView1_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles GridView1.DataBound
       GridView1.Columns(2).Visible = False
        GridView1.Columns(3).Visible = False
        GridView1.Columns(4).Visible = False   'End Sub

When I select another button from the radiobuttonlist I want this to fire (onselectchange).  It works but 

only the first column is visible. So how do I add the above code to pageload?