[Shaman]

This morning I was trying to complete Half-Life 2 for 3rd time and when I saw the snipers (the chapter that you rescue barney from the snipers).
The snipers has something like a laser sight. A beam drawn from the gun to the aimed place. I thought that we can make beam-shooting guns for CS: S.
Here is an image:
[IMG]http://**************.to/i/beamcopy.png[/IMG]
When a player fires, a beam is started to drawn. The beam keeps growing longer till it hits somewhere and when it hits it disappears.
How can I do that? (Maybe it's imposible?!?!)