projector light

hi everyone ,
this is my first post on blenderartists forum although i have been using blender for almost 2 years.
i have a project and they want the light projected from the it to have a smoky effect like the image shown below.
http://upload.wikimedia.org/wikipedia/commons/7/7c/Film_projector3.jpg
help please…

You can try messing around with the Halo option of the Spot light.

i tried that but how do i get the smoke effect…

Smoke is a whole new different topic. Check it out here:
http://www.blenderguru.com/introduction-to-smoke-simulation/