lostfocus event: if text box height exceeds n points, call sub

The idea is to make text box lostfocus event that calls sub "newpage01" when the textbox "TB01" is closed, "newpage02" when sub "TB02" is closed, etcetera. The Newpage subs add rows to accomodate the height of the textboxes. Here's what I have:

Sub addRows()
   Dim Sname As String
   Dim AddPageNum As String
   Dim snum As Integer
   Sname = Shape.Name
   snum = Format$(Shape.Name, "0#")
   AddPageNum = "newpage" & snum
 
 For Each Shape In Worksheet.Shapes
  With Shape
  If Val(Shape.Height) < 160 Then
  Else
  Call AddPageNum
   End If
  End With
End Sub

once the sub actually works, I also need to know how to use it as a lostfocus event.

Any Ideas?

Thanks,

Willardio