Issues parsing data from silverlight Modal

I have started a modal dialog from a main xaml page. when ok is click on the modal I need to add a tab to the main dialog. I tried this code but is not working. When the modal dialog is clicked, the new tab is not being added to the main page. I'm running on deadline :(
Please any help is very welcomed.


Main page entry

Code:

---

public partial class MainPage : UserControl
    {
        public MainPage()
        {
         
            InitializeComponent();
            if (((App)Application.Current).datacol.Count > 0) //checks for entry
                                                                          //before adding tab
            {
                addNewTab();
                DataContext = this;
            }
        }

---

Addind tab function

Code:

---

  private void addNewTab()
        {
            TabItem item = new TabItem();
            item.Header = "New tab";
            this.tabCases.Items.Add(item);

        }

---

Pop up code

Code:

---

private void OKButton_Click(object sender, RoutedEventArgs e)
        {
           
            ((App)Application.Current).datacol.Add(new RawData());
            int ct = ((App)Application.Current).datacol.Count;
            ((App)Application.Current).RootVisual = new MainPage(); //send
                                                                          // view to main page ??
       
            this.DialogResult = true;
        }

---