I've got a dynamic navigation, when they user clicks on a different page, that tab needs to become the active tab. Currently I'm getting NullException error and an Object error. FYI: That data is coming back fine, it's only when I try to change the tab to active it's not finding the ID.

******* Navigation Control *******

<asp:Literal ID="ltl_Navigation" runat="server"></asp:Literal>

****** Navigation Code ********

 List<Navigation> theNavigation = DataHelper.GetNavigation();
        theNavigation = theNavigation.OrderBy(u => u.OrderBy).ToList();

        foreach (Navigation item in theNavigation)
        {
            ltl_Navigation.Text += "<li ID=" + '"' + item.TabName  + '"' + " style=" + '"' + "display:" + item.Display + '"' + " class=" + '"' +              item.Class  + '"' + " runat=" + '"' + "server" + '"' + "><span><span><a href=" + '"' + item.Location + '"' + ">" + item.Title + "</a></span></span></li>";
        }

******* Default Page ***** "setting the active tab"

   HtmlGenericControl li_active = (HtmlGenericControl)Page.Master.FindControl("tab_homeactive");
        HtmlGenericControl li_inactive = (HtmlGenericControl)Page.Master.FindControl("tab_homeinactive");
        li_active.Style["display"] = string.Empty; "This is where it's erroring out!!"
        li_inactive.Style["display"] = "none";