Dear Srikanth,
I would suggest you to talk to him, and make him understand to value and love himself first, than any other person. He should know that God has given him one life, not to waste on people who don't value about him. Its nice to love and care for someone, but not so much that you forget your identity.
He should know that he is also special in his own way, and the girl was not for him. This pain will be there for some time, but plz suggest him not to loose his identity for that girl. Its better to move on with life, there are many other intresting aspects to any person's life, alongwith love.
Tell him to focus on his special intrests and qulaities, and to grow them, rather than holding her memories and ruining his life. She will not come back to pick him up, if his falls down. It is he, who has to pick himself up, and again walk with confidence.
The more you show yourself weak in this world, the more people are there to step on you and move forward.
I am saying all this b'coz of my personal experience.
Hope your friend gets courage to cope up with this stage.
Rgds,
Uma