Very sorrowful poem my friend. I'm sorry for your great friend. I share you the sadness.
You have some points to take into account:

Death never invited you
but you invited the death with pleasure
you are very close friend for us
but now death is your close friend

only the third line should read
'you were very close friend for us'

why you forget our friends?
where is your confident?
why you killed yourself?
love is your problem?
you are cheated by someone?

Why you forgot your friend?
Where was your self-confidence?
Love was your problem?
Were you cheated by someone?

still the reasons are unexplained
at last you gave us memories with tears
many peoples walking towards west in the mid night
when they are facing problems
now you also one of them

Every sentence here should start with a capital letter
'Now you became one of them'

still we can't believe your suicide
now you know the meaning for death
we miss your smiling face
we miss a man with humor

All sentences should start with capital letter
'Now you knew the meaning of death'

but you still lives in our memories.....................

'But you're still living in our memories.
(without dots, I think you understand)

My friend this aside, but believe me this poem will sound much better if you make the necessary changes.
Accept my condolance for your friend.
Thank you

This is a great tribute Mohan.He must be proud of you wherever he is my friend.

Sad poem Mohan. Suicide is always terrible to those left to mourn them.

Very well said, suicide is never the option.

Also when someone suicides, the rest of their world remains wondering why?, aside from all the hurt and sorrow that they might feel.

Sad poem, but may your friend rest in peace.