public static void fillDropDownListDepartment(DropDownList ddl)
    {
        DepartmentBAL balDepartment = new DepartmentBAL();

        ddl.DataSource     = balDepartment.SelectForDropDownList();
        ddl.DataValueField = "DepartmentID";
        ddl.DataTextField  = "DepartmentName";
        ddl.DataBind();
        ddl.Items.Insert(0, new ListItem(" --Select Department--", "-1"));
    }