select checkbox in gridview using javascript

// Convert chkDateRange CheckBoxList Cheked Event as  RadioButton Checked Event.
       function ConvertToRadio(event) {
           var chkBoxCount = document.getElementById('<%= chkDateRange.ClientID %>').getElementsByTagName("input");
           for (i = 0; i < chkBoxCount.length; i++) {
               if (chkBoxCount[i].type == 'checkbox')
                   chkBoxCount[i].checked = false;
           }
           if (event.target == null) {
               event.srcElement.checked = true;

           }
           else {
               event.target.checked = true;
           }
       }