If I understand your requirements correctly, you will need to add a textbox to your form so the user can specify a quantity when they select an item.
[assumptions]
--> Table data: My [tblSampleData] looks like this:
ID Item Rate QtyAvailable
1 Item1 Rate1 3
2 Item2 Rate2 5
--> Combo box: The Bound Column of the combo box is 1, the (hidden) first column, which is [ID].
--> Data bindings: The combo box has a Row Source (tblSampleData), but no Control Source. The list box is completely unbound.
If your situation is different they you'll need to tweak the sample code to suit.
[/assumptions]
I created a test form that looks like this when it is first opened:
The VBA code behind the form is this:
Option Compare Database
Option Explicit
Private Sub btnTransfer_Click()
Dim cdb As DAO.Database, rst As DAO.Recordset, qtySelected As Long
Set cdb = CurrentDb
Set rst = cdb.OpenRecordset("SELECT * FROM tblSampleData WHERE ID=" & Me.cbxItems.Value, dbOpenSnapshot)
qtySelected = Val(Nz(Me.txtQty.Value, 0))
If qtySelected <= 0 Then
MsgBox "Please specify a (positive) quantity.", vbExclamation
Else
If qtySelected <= rst!QtyAvailable Then
Me.lstSelected.AddItem rst!ID & ";" & rst!Item & ";" & rst!Rate & ";" & qtySelected
Else
MsgBox "Quantity selected exceeds quantity available.", vbExclamation
End If
End If
rst.Close
Set rst = Nothing
Set cdb = Nothing
End Sub
Private Sub Form_Load()
Do While Me.lstSelected.ListCount > 0
Me.lstSelected.RemoveItem 0
Loop
Me.lstSelected.AddItem ";Item;Rate;QtySelected"
End Sub
The user selects the item from the combo box...
...enters the quantity in the text box...
...and then clicks the "Transfer" button to move the item + selected quantity into the list box:
