How to set Multiple SelectedItem on Listbox?
<p>The sample code like this:</p>

<pre><code>&lt;asp:Listbox ID="ddlCat" runat="server" SelectionMode="Multiple" /&gt;

ddlCat.Items.Insert(0, new ListItem("Item1", "1"));

ddlCat.Items.Insert(1, new ListItem("Item2", "2"));

ddlCat.Items.Insert(2, new ListItem("Item3", "3"));

ddlCat.Items.Insert(3, new ListItem("Item4", "4"));
</code></pre>

<p>I want set 2 default selectedItem on Item1 and Item3, how to do this?</p>

<p>Use those code, only the latest will be selected</p>

<pre><code>ddlCat.SelectedValue = "1";

ddlCat.SelectedValue = "3";
</code></pre>

<p>Thanks a lot!!</p>
