Validation of Check box List

protected void Button1_Click(object sender, EventArgs e)

    {

        int i = 0;

        if (CheckBoxList1.Items[0].Selected){ i++; }

        if (CheckBoxList1.Items[1].Selected){ i++; }

        if (CheckBoxList1.Items[2].Selected){ i++; }

        if (CheckBoxList1.Items[3].Selected){ i++; }

        if (CheckBoxList1.Items[4].Selected){ i++; }

        if (i > 1)

        {

            Response.Redirect("abc.aspx");

            

        }

        else

        {

            Response.Write("check minimum 2 checkboxes........");

        }

    }