problems casting an object to a listbox

[foobarDividedByZero]

Hi, I have a series of pages to create that will each have a bunch of listboxes on them, each containing a listing of files in a directory. I'm trying to get the page down to basics where i only have to plug in the correct paths to the folders, but I'm hitting a problem casting 'object sender' to a listbox - the SelectedItem is always the first item, not what was actually selected. here is the entire code-behind (stripped down to basics): public partial class departments_safety_play : System.Web.UI.Page { private static readonly string year = DateTime.Now.Year.ToString(); private static readonly string root = @"../..//FIBRELINE/"; private readonly string pathFibrelineA = string.Format(@"{0}{1}/A-SHIFT/", root, year); protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { string folderToBrowse = Server.MapPath(pathFibrelineA); utilityLib.ShowFilesInWithValue(folderToBrowse, lstFibrelineA, pathFibrelineA); } } protected void lbSelectedIndexChanged(ListBox lb) { string dir = lb.SelectedValue + lb.SelectedItem.Text; string popupScript = "" + "window.open('" + dir + "', 'CustomPopUp', " + "'width=600, height=500, menubar=1, resizable=1, location=1')" + ""; ClientScript.RegisterStartupScript(GetType(), lb.SelectedItem.Text, popupScript); } protected void SelectedIndexChanged(object sender, EventArgs e) { ListBox lb = (ListBox) sender; lbSelectedIndexChanged(lb); } }