W're almost at the end! :-) Only 3 steps left. First we have to define a healt criteria for our web appliction and after that we can create our distributed appliction that will drive ou service level dashboard.   Use the Web Application Editor to choose what conditions will cause an error or warning during a synthetic transaction. For the Service Level Dashboard, an error is equivalent to an availability exception, and a warning is equivalent to a performance exception. Availability exceptions...(read more)

Read the complete post at http://scug.be/blogs/scom/archive/2008/10/22/define-a-health-criteria-for-your-web-application-monitor.aspx