<p>I have a couple of dropdown boxes on a normal ASP.Net page.</p>

<p>I would like the user to be able to change these and to have the page Pseudo-post back to the server and store these changes without the user having to hit a save button.</p>

<p>I don't really need to display anything additional as the dropdown itself will reflect the new value, but I would like to post this change back without having the entire page flash due to postback </p>

<p>I have heard that this is possible using AJAX.Net... </p>

<p>Can someone point me in the right direction?</p>

Add a reference to System.Web.Extensions and System.Web.Extensions.Design to your website.  Then put a scriptmanager on your page and wrap your ddl in an updatepanel.  Do whatever you want on the back-end.
For example...
```
```
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
  <ContentTemplate>

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true" OnSelectedIndexChanged="yourDDL_SelectedIndexChanged">
</asp:DropDownList>

  </ContentTemplate>
</asp:UpdatePanel>

protected void yourDDL_SelectedIndexChanged(object sender, EventArgs e)
{
// do whatever you want
}
```
```