or
function RadComboBoxKeyPressing(combo, eventArgs) { var key = eventArgs.get_domEvent().keyCode; var allow = decOnlyKey(key, combo.get_text());// if (!allow)// eventArgs.set_cancel(true);}<tr id="trForwardEmail" runat="server"> <td> Forward Email To: </td> <td width="10"> </td> <td> <telerik:RadComboBox ID="cmboForwardEmail" runat="server" width="200" OnClientSelectedIndexChanging="ShowCheckbox"/> </td> </tr>function ShowCheckbox(sender, eventArgs) { var checkbox = document.getElementById("<%= trSaveEmail.ClientID %>"); var cmboBox = $find("<%= cmboForwardEmail.ClientID %>"); alert(cmboBox.get_text()); if(cmboBox.get_selectedItem().get_text() != "No Forwarder") { checkbox.style.visibility = "hidden"; } else { checkbox.style.visibility = "visible"; }}<telerik:RadComboBox ID="rcbLocation" runat="server" AllowCustomText="True" DataSourceID="sdsLocation" DataTextField="Location_Name" DataValueField="Location_ID" MarkFirstMatch="True"> </telerik:RadComboBox> rcbLocation.DataBind(); rcbLocation.SelectedValue = ReturnedData["Master_Location"].ToString();