Address from global and contact list in text box

I am trying to get all the contacts from global address and normal contact list in a list box in this format: lastname,firstname

all the names are displayed in a listbox.
User will select any of these names and say add.

All the email address of the seleted names should be displayed in a textbox.

Code:

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If objform.lstContactList.SelCount > 0 Then
        'For each item in List1...
        For i = objform.lstContactList.ListCount - 1 To 0 Step -1
            ' if it's selected then..
            If objform.lstContactList.Selected(i) Then
                '..store it in the array
                sUserChoices(z) = objform.lstContactList.List(i)  ' it contain john,n
                'For sUserChoices = 0 To SelCount - 1
                Txtname.Text = Txtname.Text & sUserChoices(z) & "; "  'here its adding that name to textbox, but i want the email address to be in the textbox
                z = z + 1
            End If
        Next

    End If

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