How to select Only One CheckBox In Grid View

 <script type="text/javascript">
     function CheckOne(obj) {
         var grid = obj.parentNode.parentNode.parentNode;
         var inputs = grid.getElementsByTagName("input");
         for (var i = 0; i < inputs.length; i++) {
             if (inputs[i].type == "checkbox") {
                 if (obj.checked && inputs[i] != obj && inputs[i].checked) {
                     inputs[i].checked = false;
                 }
             }
         }
     }
    </script>


and Use This

<asp:CheckBox ID="chkSelect" runat="server" onclick ="CheckOne(this)"
     />