How can I programatically get child's content text and value from stackpanel in WPF ?

hi, 

I am trying to get textbox value from a stackpanel. That stackpanel is a child of a popup. it is easy to add a stackpanel with its children into a popup content as child. But I cant succes reaching the value of textbox in that stackpanel. 

My codes for creating popup 

 Dim pop As New Popup
        Dim text As New TextBlock
        Dim text1 As New TextBox
        Dim del As New Button
        del.Height = 30
        del.Content = "delete"
        AddHandler del.Click, AddressOf del1_clicked
        Dim save As New Button
        save.Height = 30
        save.Content = "save"
        AddHandler save.Click, AddressOf save1_clicked
        Dim ttt As New Button
        ttt.Height = 30
        ttt.Content = "exit"
        AddHandler ttt.Click, AddressOf ttt1_clicked
        Dim sp As New StackPanel
        sp.Height = 150
        sp.Width = 200
        Dim row1 As DataRowView = DataGrid1.SelectedItems(0)
        text.Text = row1(0).ToString
        text1.Text = row1(1).ToString
        pop.Height = 150
        pop.Width = 200
        pop.HorizontalAlignment = Windows.HorizontalAlignment.Stretch
        pop.VerticalAlignment = Windows.VerticalAlignment.Center
        pop.Placement = System.Windows.Controls.Primitives.PlacementMode.Mouse
        pop.AllowsTransparency = True
        text.Background = Brushes.OrangeRed
        sp.Children.Add(text)
        sp.Children.Add(text1)
        sp.Children.Add(del)
        sp.Children.Add(save)
        sp.Children.Add(ttt)
        pop.Child = sp
        pop.Visibility = Windows.Visibility.Visible
        pop.IsOpen = True
        StackPanel2.Children.Add(pop)

with these codes I can call a popup menu via clicking a datagrid row. After opening popup I need the strings contained in textbox and textblock. 

The image of popup

As you see, there are a textblock, a textbox and three buttons on the popup menu. I just need the values of prgramatically created textboxt and textblock for buttons' click events. 

For save button's click event  what have to I do ? 

    Private Sub save1_clicked(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Dim but As Button = sender
        Dim sc As StackPanel = but.Parent
        Dim pop As Popup = sc.Parent
	!!!!! dim txt as textbox = child of stackpanel ,  what I need to write here ????
	!!!!! dim txt as textblock = child of stackpanel , what I need to write here ????
    End Sub

Thanks in advance