Originally posted by "marinus"...

There is this Access database. Part of it manages inventory. There is a large storage, in which crates of different stuff from different sources are stored, and in the Access database there is a form onto which this information is entered. There are 38 rows of 10 columns of crates and the height varies.

The form is graphical. You can enter a row number and it will give you a graphical view of it, which you can change by clicking the crates on and off. The crates and their positions are stored in a table. The individual crates are represented by labels, some of which will be hidden because of the varying height of the roof.

The code is horrendous. Below are the 'load' and 'save' routines:

Now, selecting a crate is done this way:

Those look like arrays, don't they? Well, they are. If you have ever programmed in VB, you might think of control arrays.
You are mistaken.
and so on, for each and every possible crate. And, because events need to be registered as well,

Private Sub Bijschrift76_click(): Call kist(0, 0): End Sub
Private Sub Bijschrift77_click(): Call kist(1, 0): End Sub
Private Sub Bijschrift78_click(): Call kist(2, 0): End Sub
Private Sub Bijschrift79_click(): Call kist(3, 0): End Sub
Private Sub Bijschrift80_click(): Call kist(4, 0): End Sub
Private Sub Bijschrift76_DblClick(Cancel As Integer)
   Call kist_r(0, 0)
End Sub

Private Sub Bijschrift77_DblClick(Cancel As Integer)
   Call kist_r(1, 0)

End Sub
Private Sub Bijschrift78_DblClick(Cancel As Integer)
   Call kist_r(2, 0)
End Sub

With about 80% filled, it takes about one and a half minute to come up, about fifteen seconds to switch to another row, and about five seconds for something to happen after you click one of the crates. Printing is done by turning all control elements' Visible property off except for the labels representing crates, printing the form, and turning the control elements back on.

  Set knoppenlijst(0, 0) = Bijschrift76
  Set knoppenlijst(1, 0) = Bijschrift77
  Set knoppenlijst(2, 0) = Bijschrift78
  Set knoppenlijst(3, 0) = Bijschrift79
  Set knoppenlijst(4, 0) = Bijschrift80

Private Sub kist(x%, Y%)
 On Error GoTo fail
 tdr_id_s(x%, Y%, curr_rij%) = tdrid_list.Value
 Dim Naam$, ras$, Perceelnr$
 Call naam_en_ras_en_perceelnr(tdrid_list.Value, Naam$, ras$, Perceelnr$)
 If (k_(CInt(tdrid_list.Value))) = 0 Then
    k_(CInt(tdrid_list.Value)) = x_kleur%
    x_kleur% = ((x_kleur% + 1) Mod 3) + 1
 End If
 knoppenlijst(x%, Y%).Caption = Naam$ + vbCrLf + ras$ + vbCrLf + Perceelnr$
 knoppenlijst(x%, Y%).BackColor = kleuren(k_(CInt(tdrid_list.Value)), 0)
 knoppenlijst(x%, Y%).ForeColor = kleuren(k_(CInt(tdrid_list.Value)), 1)
 gewijzigd = True
 Exit Sub
 Exit Sub
End Sub

Private Sub kisten_van_database()
   Dim qd As QueryDef
   Set qd = CurrentDb.CreateQueryDef("kisten_laad", "SELECT x,y,z,tdrid FROM kisten")
   Dim rs As Recordset
   Set rs = qd.OpenRecordset()
   x_kleur% = 1
   On Error GoTo x
   While True 'For i = 1 To rs.RecordCount
      x% = CInt(rs.Fields(0).Value) 'x
      Y% = CInt(rs.Fields(1).Value) 'y
      z% = CInt(rs.Fields(2).Value) 'z
      tdr_id_s(x%, Y%, z%) = Val(rs.Fields(3).Value)
      p_tdr_id_s(x%, Y%, z%) = Val(rs.Fields(3).Value) 
      If k_(tdr_id_s(x%, Y%, z%)) = 0 Then
         k_(tdr_id_s(x%, Y%, z%)) = x_kleur%
         x_kleur% = ((x_kleur% + 1) Mod 3) + 1
      End If
   Wend 'Next i 
   CurrentDb.QueryDefs.Delete "kisten_laad"
   gewijzigd = False
End Sub

Private Sub kisten_naar_database()
  For z% = 0 To 37
     For Y% = 0 To 5
        For x% = 0 To 9
           sqlcmd$ = ""
           If tdr_id_s(x%, Y%, z%) > 0 Then
              If Not tdr_id_s(x%, Y%, z%) = p_tdr_id_s(x%, Y%, z%) Then
                 If p_tdr_id_s(x%, Y%, z%) > 0 Then
                    sqlcmd$ = "UPDATE kisten " & _
                              " SET tdrID=" & CStr(tdr_id_s(x%, Y%, z%)) & _
                              " WHERE x=" & CStr(x%) & _
                              " AND y=" & CStr(Y%) & " AND z=" & CStr(z%)
                    sqlcmd$ = "INSERT INTO kisten (x,y,z,tdrId) VALUES (" & _
                              CStr(x%) & "," & CStr(Y%) & "," & CStr(z%) & "," & _
                              CStr(tdr_id_s(x%, Y%, z%)) & ")"
                 End If
              End If
             If p_tdr_id_s(x%, Y%, z%) > 0 Then
                sqlcmd$ = "DELETE FROM kisten WHERE x=" & CStr(x%) & _
                          " AND y=" & CStr(Y%) & " AND z=" & CStr(z%)
             End If
           End If
           If sqlcmd$ <> "" Then
              Application.DoCmd.RunSQL sqlcmd$
              p_tdr_id_s(x%, Y%, z%) = tdr_id_s(x%, Y%, z%) 'dit lijkt me duidelijk
           End If
        Next x%
     Next Y%
  Next z%
  gewijzigd = False
End Sub