بدست اورت متن RadEditor توسط جاوا اسکریپت در Asp.Net

<asp:ScriptManager runat="server" ID="ScriptManager1">
    <Scripts>
        <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
    </Scripts>
</asp:ScriptManager>

<script>
 $(document).ready(function () {
    $('#btn_Show').click(function () {
    var editor = $find("<%= txtDescription.ClientID %>"); //get a reference to RadEditor's client object
    alert(editor.get_html()); //returns RadEditor Content
 });
});
</script>

<asp:ScriptManager runat="server" ID="ScriptManager1">
    <Scripts>
        <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
    </Scripts>
</asp:ScriptManager>