vlookup in vba
 

I want to use a vlookupfunction in vba but I don't get any result from this
module. I've inserted the module. Can someone figure out what I'm doing
wrong and give me some assistance to make it work ?

Many thanks

Sub update_uren()
a = Sheets("uuroverzicht").Cells(2, 2)
For b = 1 To 12
If Sheets("data").Cells(b, 2) = a Then
c = Sheets("data").Cells(b, 1)
For d = 7 To 1000
If Sheets("globaal uuroverzicht").Cells(d, 2) = c Then
For k = 4 To 43
For j = 9 To 27
Sheets("globaal uuroverzicht").Cells(d, j) =
Application.WorksheetFunction.VLookup(Sheets("uuro verzicht").Cells(k, 1),
Sheets("uuroverzicht").Range("$a$4 : $ab$38"), j, False)
Next
Next
End If
Next
End If
Next
End Sub