Developper un code Macro condition

Bonjour mes amis,
veuillez m'aider a développer cette macro? voila le code:
l'objet de la macro est: Donner un tableau d'alerte contient toutes les entreprises qui j'ai pas encore payé leurs impôts, l'alerte commence 10 jour avant la date de paiement sinon il n'affiche pas.
voila le fichier ci-joint explique la tache, mais l'ordre de son travail ne marche pas,
si vous avez d'autre questions merci de les poser,
cordialement
http://www.cjoint.com/c/EGjnvxyeYzy

Sub tax()
Dim tx As String
Dim tx2 As String
Dim tx3 As String
Dim tx4 As String
Dim tx5 As String
 
Dim ans As Integer
 
Dim tgt As Date
Dim alt As Double
Dim i As Long
 
tgt = Format(Date, "dd/mm/yyyy")
Range("B2").Select
For i = 1 To 4
If i = 1 Then
 
 
Do
alt = ActiveCell.Offset(0, 1).Value - tgt
If ActiveCell.Value = "" And alt < 0 Then
tx5 = ActiveCell.Offset(0, -1).Value & " (" & Range("B1").Value & ")" & " - " & "[ " & -1 * alt & "]" & " Days Over due "
 
If MsgBox("Did you pay tax for this" & vbCrLf & tx5, vbYesNo) = vbYes Then
ActiveCell.Value = "x"
Else
 
End If
End If
 
 
If ActiveCell.Value = "" And alt <= 10 Then
 
tx = tx + vbCrLf + ActiveCell.Offset(0, -1).Value & " (" & Range("B1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
End If
ActiveCell.Offset(1, 0).Select
 
Loop Until ActiveCell.Offset(1, -1).Value = ""
 
ElseIf i = 2 Then
 
Range("D2").Select
Do
alt = ActiveCell.Offset(0, 1).Value - tgt
 
If ActiveCell.Value = "" And alt < 0 Then
 
tx5 = ActiveCell.Offset(0, -3).Value & " (" & Range("D1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
 
If MsgBox("Did you pay tax for this" & vbCrLf & tx5, vbYesNo) = vbYes Then
ActiveCell.Value = "x"
Else
 
End If
End If
 
 
If ActiveCell.Value = "" And alt <= 10 Then
 
tx2 = tx2 + vbCrLf + ActiveCell.Offset(0, -3).Value & " (" & Range("D1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
End If
ActiveCell.Offset(1, 0).Select
 
Loop Until ActiveCell.Offset(1, -1).Value = ""
 
 
ElseIf i = 3 Then
 
Range("F2").Select
Do
alt = ActiveCell.Offset(0, 1).Value - tgt
 
If ActiveCell.Value = "" And alt < 0 Then
 
tx5 = ActiveCell.Offset(0, -5).Value & " (" & Range("F1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
 
 
If MsgBox("Did you pay tax for this" & vbCrLf & tx5, vbYesNo) = vbYes Then
ActiveCell.Value = "x"
Else
 
End If
End If
 
If ActiveCell.Value = "" And alt <= 10 Then
 
tx3 = tx3 + vbCrLf + ActiveCell.Offset(0, -5).Value & " (" & Range("F1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
End If
ActiveCell.Offset(1, 0).Select
 
Loop Until ActiveCell.Offset(1, -1).Value = ""
 
 
ElseIf i = 4 Then
 
Range("H2").Select
Do
alt = ActiveCell.Offset(0, 1).Value - tgt
 
If ActiveCell.Value = "" And alt < 0 Then
 
tx5 = ActiveCell.Offset(0, -7).Value & " (" & Range("H1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
 
 
If MsgBox("Did you pay tax for this" & vbCrLf & tx5, vbYesNo) = vbYes Then
ActiveCell.Value = "x"
Else
 
End If
End If
 
If ActiveCell.Value = "" And alt <= 10 Then
 
tx4 = tx4 + vbCrLf + ActiveCell.Offset(0, -7).Value & " (" & Range("H1").Value & ")" & " - " & "[ " & alt & "]" & " Days left to pay "
End If
ActiveCell.Offset(1, 0).Select
 
Loop Until ActiveCell.Offset(1, -1).Value = ""
 
End If
 
Next
 
 
MsgBox tx & vbCrLf & tx2 & vbCrLf & tx3 & vbCrLf & tx4
 
 
 
End Sub