Mark All Products From Subform

I have a form orders with a subform orderdetails where we can order more than one product. When the order is finished you save it with a save button where it will also automathically mark the products ordered as not available.
Now, this code works, the problem is that it only marks one product. how do you make it mark all the products that where ordered (in orderdetails - the subform)? :


DoCmd.DoMenuItem acFormBar, acRecordsMenu, acSaveRecord, , acMenuVer70
'set values here!
'loop?
Dim stAvai As String
Dim strSetProd As String

stAvai = "= " & Me.OrderDSubform.Form!ProductIdctrl.Value & " "
strSetProd = "UPDATE Products " & _
"SET Products.[Avail]= True " & _
"WHERE Products.[ProductId]" & stAvai & " ;"
DoEvents
DoCmd.RunSQL strSetProd