Meaning of this sentense: "He must become happy."

[Arya]

If i say "He must become happy."
What does it mean?
Is it right?

[Domles]

I think "must" here is equal to "should". So the whole means "in this situation he should become happy because smth is favourable to him".
If you say "He must have become happy" this means that you think, he is happy now due to some occurence. This is your assumption.
But that's only my guess ;)

[Thirupathaiah]

hi.......
I think He must be happy.