UpdatePanel populated at runtime from codebehind

Question

Hi,

i am populating an updatepanel at runtime with a listbox and a button.

On the client side i select an item from the listBox and i press the  button. The button triggers the refresh of the updatepanel.But the problem is on the server side i don't know how to get the listbox selected item.

I am doing something like this:

if (ScriptManager1.IsInAsyncPostBack)

{

string fromWhere = Request[ScriptManager1.ID];

if (fromWhere.Contains("button1"))

{

//here i would need the listbox selected item,but that property is empty. Any ideas?

}

}