Singning/Logging Different Accounts on One Yahoo Messenger Running

Can someone help me. I have different accounts, many account (to keep in touch with my friends) on my yahoo messenger.. I think it is possible cause iI already saw some are doing this..

Can I used different account on One Yahoo Messenger running.. without installing or download patch w/c i already did.. yes it worked out but thats not what i want it to be because it opens multi Yahoo Messenger compare to the one that i saw it opens one Yahoo Messenger but you can sing in many accounts..

Techrepublics how about this still no replies?????

HELPPPPPPPPPPPPPP!!!!!!!!!!!!!!!!
Someone, Anybody, Anyone