Mandatory Merged Cell Input for excel 2016

Question

I had a merged cell from D4 to H4, I want the cells to be mandatory. I had tried the following code but does not work.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim c As Range
Dim cel As Range

Set c = Range("D4:H4")

Application.EnableEvents = False
If Not Intersect(Target, c) Is Nothing Then
  For Each cel In c
    If cel.Text = "" Then
      Application.Goto reference:=c, Scroll:=True
      MsgBox ("Field Cannot Be Blank")
      Exit For
    End If
  Next cel
End If
Application.EnableEvents = True
End Sub

I also had another cell need to be mandatory, H2. This code already works, I want to combine the codes for D4 to H4 and H2 together.

Private Sub Workbook_BeforeClose(Cancel As Boolean)
If Cells(2, 8).Value = "" Then
  MsgBox "Cell H2 requires user input", vbInformation, "Please filled up the 
  mandatory cells"
  Cancel = True
End If
End Sub

Any help and suggestion is appreciated.

Answer 1

Thanks to @Rik Sportel, I tried to remerged the cells and apply elseif statement and it works now.

Private Sub Workbook_BeforeClose(Cancel As Boolean)
If Cells(4, 4).Value = "" Then
  MsgBox "Cell D4 requires user input", vbInformation, "Please filled up the mandatory cells"
  Cancel = True
ElseIf Cells(2, 8).Value = "" Then
  MsgBox "Cell H2 requires user input", vbInformation, "Please filled up the mandatory cells"
  Cancel = True
End If
End Sub