I am Using this code...
My code is..
<script type="text/javascript">
$("#lbx_FundType").select2();
$("#checkbox").click(function () {
if ($("#checkbox").is(':checked')) {
$("#lbx_FundType > option").prop("selected", "selected");
$("#lbx_FundType").trigger("change");
} else {
$("#lbx_FundType > option").removeAttr("selected");
$("#lbx_FundType").trigger("change");
}
});
</script>
<script type="text/javascript">
<input type="checkbox" runat="server" onchange="return CheckChanged(event);" id="checkbox" />Select All
<select id="lbx_FundType" class="chzn-select span4" runat="server"> </select>