Working With Templatefield in GridView

protected void rbSelector_CheckedChanged(object sender, System.EventArgs e)
{
    //Clear the existing selected row 
    foreach (GridViewRow oldrow in GridView1.Rows)
    {
        ((RadioButton)oldrow.FindControl("rbSelector")).Checked = false;
    }
    //Set the new selected row
    RadioButton rb = (RadioButton)sender;
    GridViewRow row = (GridViewRow)rb.NamingContainer;
    ((RadioButton)row.FindControl("rbSelector")).Checked = true;
    ((TextBox)row.FindControl("textBoxID")).Focus();
}