can i withdraw my instant message in yahoo messenger if my friend is offline?How?

for the main question. no, you can't withdraw any sent message.

Once it's sent...u can't take it back--much the same goes for email.

You can appear offline when you're otherwise--and choose who knows you're online. That's pretty much it as far as that goes.

you can make custom availibilities on msger, like sleeping now come back later, I dont think you can retract a msg.