Question

I have a DDL and ASP.NET Textbox. I would like to populate the text box with the option I choose from the DDL. I need this to be instant and not use postbacks so it would seem JavaScript would be the obvious choice here. I have done quite a bit of searching but everything I have found seems to be for standard HTML (Selects and Inputs) and these do not appear to work with ASP objects:

<asp:DropDownList runat="server" ID="DDLSalesPerson" DataValueField="keyid" DataTextField="FullName" />

<asp:TextBox runat="server" id="txtSalesPerson" />

My DDL is populated from SQL in the code-behind page.

Can somebody assist with the appropriate code I should use? Thanks.

Answer 1

If you’re new to JavaScript, use the jQuery library (simply provide references to the CDN-hosted jQUery files at google.com) and then you can use the following code:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script>
<script language="javascript" type="text/javascript">
    $("#DDLSalesPerson").change(function () {
        $("#txtSalesPerson").val($(this).val());
    });
</script>