Trojan.Fakeavalert showing in Security History

While my son was on the internet he clicked on something and the screen went black and some Trojan Worm message appeared.  I was not at home at the time but my wife immediately turned off the computer.  When I got home I started the computer and clicked on my Norton Internet Security 2009 icon and made sure my virus defs were up to date and am currently running a full scan.  While the scan is running I checked in the History and found this info:

 

Severity shows High.....Activity shows Auto-Protect has detected Trojan.Fakeavalert  with the time/date ....Status shows Blocked....Recommended Action shows Resolved-No Action

 

I also noticed it submitted it to Norton Community watch.....Status shows Processing....Recommended Action shows No Action Required.

 

A long explanation to try and find out if someone can tell me if my computer is actually infected or not?  So far nothing has been detected by the scan