door window button unit

[X52021]

Hi all, I have a problem with my drivers side door window button. All buttons work as they should, apart from the drivers window button only brings the window down, not back up, I figured this out by swapping switches on doors, so I have the passenger side button unit plugged into my drivers side, and the window went up again! does anybody know of a good fix for this, or second option, if not, where is best to buy the drivers side window button unit? thanks guys, and I have already fixed more then I could imagine because of this site, its been such a great help thanks a lot.
I love this site almost as much as I love my E53.