check only one checkbox in gridview

i have list of items which have checkboxes in front,
so i try to only allow only one checkbox can be checked in the gridview.

<asp:GridView ID="gvLS" runat="server" 
        AutoGenerateColumns="False" AllowPaging="True" CssClass="datatable"
                    CellPadding="5" BorderWidth="1px" BorderColor="#6E6E6E" 
                 Font-Names="Arial" Font-Size="Small" 
                PageSize="5" GridLines="None" AlternatingRowStyle-BackColor="#efefef" 
            Width="300px" 
                 HeaderStyle-HorizontalAlign="Left" 
            AllowSorting="True"   >
                    <HeaderStyle BackColor="#BDBDBD" />
                    <Columns>
                    <asp:TemplateField>
                        <ItemTemplate>
                            <asp:CheckBox id="cbCheckLevel" runat="server" />
                            <asp:Label ID="lblIDField" Visible="false" Text='<%# Eval("id") %>' runat="server" />
                    
                         </ItemTemplate>
                    </asp:TemplateField>

                    <asp:BoundField HeaderText="Level Code" DataField="code" 
                            SortExpression="code" HeaderStyle-ForeColor="Black"
                            HeaderStyle-CssClass="first" ItemStyle-CssClass="first" ReadOnly="True"  
                            HeaderStyle-HorizontalAlign="Left"  ItemStyle-HorizontalAlign="Left">
<HeaderStyle CssClass="first" ForeColor="Black"></HeaderStyle>

<ItemStyle CssClass="first"></ItemStyle>
                        </asp:BoundField>
                        
                            <asp:BoundField HeaderText="Level Name" DataField="name" 
                            SortExpression="name" HeaderStyle-ForeColor="Black"
                            HeaderStyle-CssClass="first" ItemStyle-CssClass="first" ReadOnly="True"  
                            HeaderStyle-HorizontalAlign="Left"  ItemStyle-HorizontalAlign="Left">
<HeaderStyle CssClass="first" ForeColor="Black"></HeaderStyle>

<ItemStyle CssClass="first"></ItemStyle>
                        </asp:BoundField>
                       
                     
                    </Columns>
        
                         </asp:GridView>

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