Well in that case I want to share my opinion. I think laughing is not connected with inner joy; it’s more superficial rather .Whereas smile is associated with real happiness of heart.
Let me give an example. Yesterday there was a huge conference and quite a lengthy one. I managed to stay attentive for couple of hours but then my mind started wandering in some far away lands of Ulysses (may be I was reading the poetry the night before).
I was woken by a thud of laughter in the conference room. Something the orator said provoked the laughter in all. (Am sorry I can not really share with you all since I did not hear it myself).
I don’t know but I joined the laughter very stupidly, I admit.
Somehow I manage to ask my fellow colleague the reason behind.
To my surprise he said he did not hear it and was laughing so that others may not identify him as inattentive. I was really amused and I ‘smiled’.
I discovered how the meaning is different though it is suppose to show the same feeling.
I realized how we are making fool of ourselves; how our inner conscious part mock at our foolish endeavor to prove ourselves smart.
In our life many time we smiled,which really touched our heart and we can remember most of them .But can we recollect a happy instance where we have laughed? I think a person can laugh thousand times a day but smile only occasionally.
I realized; to smile I don’t need promotion, neither a trip to Switzerland. A small dew drop at the edge of grass can make me smile. The little underprivileged children playing with dust can make me smile, watching the sunset in my roof can make me smile…………..
And I don’t think there is any sort of “smile club”?
But I know one thing; one can smile if he wants to .Only requirement is: give mind the time to wander, to feel, to listen and to relish the very ordinary life with extraordinary beauty in it.
The sincere effort needed is to open the locks of seriousness, responsibility and other for a while and free the mind, let it enjoy the breeze and lilies of moments……….
I understand this small smile may not be spectacular but effective enough to be happy and light from inside; to savor the wonderful life we are grant to and sometime to make some one else happy…………

And by the way who do not want to be happy?
That’s why may be it is said, “Smile is the only curve that set things right”
Keep smiling !!!!