How do I select all checkbox's in a checkbox list on a button click using c sharp
<asp:CheckBoxList ID="CheckBoxList1" runat="server" RepeatColumns="5">
<asp:ListItem>1</asp:ListItem>
<asp:ListItem>2</asp:ListItem>
<asp:ListItem>3</asp:ListItem>
<asp:ListItem>4</asp:ListItem>
<asp:ListItem>5</asp:ListItem>
</asp:CheckBoxList>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Select All" />