protected void lboxSchools_SelectedIndexChanged(object sender, EventArgs e) { lboxUsers.Items.Clear(); if (lboxSchools.SelectedItem != null) { System.Collections.Generic.List <User> userList = new System.Collections.Generic.List <User>(Schools.GetUsersInSchool(Convert.ToInt64(lboxSchools.SelectedValue))); userList.Sort(); lboxUsers.DataSource = userList; lboxUsers.DataBind(); } }