WHISPER it quietly. But today is Friday 13th. Or did a message appear on your computer screen warning you of the fact? If so, you could have been the victim of one of the more common computer viruses.

But fears that hard disks everywhere will crash and information disappear appear to be largely unfounded. While there are about 100 "Friday 13th" viruses, most are rare and are combated by anti virus software.

The Margin applauds the wicked mind who thought up the "Thursday 12th" virus, which jumps up on the screen warning of doom and destruction the next day.

One computer expert was quoted this week dismissing the whole virus thing as a "cyber urban myth" designed to sell expensive computer protection systems.

A few computer crashes in Dublin yesterday led to word going round town that a virus was loose. But the truth appears to have been that it was just the usual old problems.