Following my title, I don't know why it not working. Please help me !. Please show code if need. here my code
<asp:DropDownList ID="ddl" runat="server" ClientIDMode="Static" OnSelectedIndexChanged="ddl_SelectedIndexChanged"></asp:DropDownList>
<asp:Label ID="label" runat="server" ClientIDMode="Static" CssClass="field" Width="150px"></asp:Label>
<script type="text/javascript">
$(function () {
$("#ddl").change(function (e)
{
var itemExists = false;
var txt = $("#label").val();
e.preventDefault();
$("#ddl option").each(function () {
if ($(this).text() == $.trim(txt))
{
itemExists = true;
alert('Item already exists'
); }
});
}); });
</script>