Is it possible to insert the inputed values of an userform into the last row
of 3 different worksheets (with unique names) where no data has been filled
in yet ? I have already tried the underneath but the macro stops when it has
to tackle the next sheet. Is there a way to solve this problem ?

Sub cmdok_click()
Sheets("uuroverzicht").Cells(4, 1).Select
Selection.End(xlDown).Select
ActiveCell.Offset(1, 0).Range("A1").Select
For a = 4 To 100
If Sheets("uuroverzicht").Cells(a, 1) = ActiveCell Then
Sheets("uuroverzicht").Cells(a, 1).Value = txtSDnr.Text
Sheets("uuroverzicht").Cells(a, 2).Value = txtvoornaam.Text
Sheets("uuroverzicht").Cells(a, 3).Value = txtachternaam.Text
Sheets("uuroverzicht").Cells(a, 4).Value = txtgeboortedatum.Text
Sheets("uuroverzicht").Cells(a, 5).Value = txtindienst.Text
Sheets("uuroverzicht").Cells(a, 7).Value = txtABM.Text
Sheets("uuroverzicht").Cells(a, 8).Value = txtMF.Text
Sheets("uuroverzicht").Cells(a, 9).Value = cboafdeling.Text
End If
Next
Sheets("globaal uuroverzicht").Cells(496, 1).Select
Selection.End(xlDown).Select
ActiveCell.Offset(1, 0).Range("A1").Select
For b = 6 To 1000
If Sheets("globaal uuroverzicht").Cells(b, 1) = ActiveCell Then
Sheets("globaal uuroverzicht").Cells(b, 1) = txtSDnr
Sheets("globaal uuroverzicht").Cells(b, 2) = txtvoornaam
Sheets("globaal uuroverzicht").Cells(b, 3) = txtachternaam
Sheets("globaal uuroverzicht").Cells(b, 4) = txtgeboortedatum
Sheets("globaal uuroverzicht").Cells(b, 5) = txtindienst
Sheets("globaal uuroverzicht").Cells(b, 6) = txtABM
Sheets("globaal uuroverzicht").Cells(b, 7) = txtMF
Sheets("globaal uuroverzicht").Cells(b, 8) = cboafdeling
End If
Next
End Sub

Greetings