Removing highlight from list boxes (1 Viewer)

I have a form with two list boxes showing data from two different tables.

The user double clicks on an item in the first list box which puts the value into a separate text box. They then select one or more items from the second list box which combine the answers in the text box. The resulting answer is subsequently placed into a memo field on another form. I hope all that makes sense.

My problem is when you select from either list box, the items selected are highlighted. This is OK but I want the highlight to go once the item has been put into the text box, leaving a clean list box again. I tried BackColor but that doesn't work.

Any ideas?

This will allow you to deselect everthing in a list box named "MyListBox"

Works perfectly

Thanks for your help