title: Populate a TextBox from a DropDownList selection ASP.NET/Javascript
body: <p>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:</p>
  
  <pre><code>&lt;asp:DropDownList runat="server" ID="DDLSalesPerson" DataValueField="keyid" DataTextField="FullName" /&gt;
  
  &lt;asp:TextBox runat="server" id="txtSalesPerson" /&gt;
  </code></pre>
  
  <p>My DDL is populated from SQL in the code-behind page.</p>
  
  <p>Can somebody assist with the appropriate code I should use? Thanks.</p>