louponne - 1:58 pm on Dec 31, 2007 (gmt 0)

Oliver, there are many ways to do this - one would be to set up real-time calls (web services or other) between the two systems that would "inform" them of sales. Another solution would of course be a nightly sync of the two databases, but then the stock indicated on either side would not be in real-time since it wouldn't be taking into account the day's sales.