Making a particuliar smoke effect

Help me, i’m still fairly new in flash…but I want to make a swirling bit of smoke for a banner i’m designing. i looked everywhere, but i couldn’t find a tutorial about this particular effect. how do you reproduce an effect like the smoke coming from the shotgun on this? check out http://[URL=“http://www.50cent.com”]www.50cent.com to see what i mean. what is those lines called?