title: Message box appears multiple times
body: <p>With my code:  </p>
  
  <pre><code>Private Sub Worksheet_Change(ByVal Target As Range)
   Set Target = Me.Range("D10", "D17")
   Dim KeyCells As Range
   Set KeyCells = Range("D10", "D17")
  
  If Not Application.Intersect(KeyCells, Range(Target.Address)) Is Nothing Then
      If Range("D10").Value &lt; 31.35 Then
       Ans = msgbox("The accumulated Rain fall for this week is insuficient." &amp; vbNewLine &amp; "Click Yes if it was irrigated" &amp; vbNewLine &amp; "Click No if not", vbYesNo + vbCritical, "Rainfall Insufficient")
  
  
      End If
  End If
  
  Select Case Ans
              Case vbYes
                 Range("E10").Value = "Yes"
                  Exit Sub
              Case vbNo
                  Range("E10").Value = "No"
                  Exit Sub
            End Select
  
  
  
  End Sub
  </code></pre>
  
  <p>the message box appears multiple times but when I comment the <code>Select Case</code> it disappears.  </p>
  
  <p>Why?</p>