VB Code

I doing this program where by The person selects parts from a list box, then clicks a transfer button to place the selected item in another list box (eg shopping trolley)on the same form.
The problem I have is when I transfer the contents of the shopping trolley to another form like a print preview, listing all items selected from the first form, I can’t get it to work.

I was wondering if someone else may have a piece of code that I could use to fix my problem.

Thanks for your help
Claude