Tears X Smile

If someone is smiling,
U will think that He or She is happy;
But if someone is crying,
U will think that He or She is sad...
Actually,
Noone knows that THE FACES BEHIND THE SMILE
and THE FACES BEHIND THE TEARS,
maybe the time he or she is smiling or crying,
he or she is really happy or sad,
BUT SOMETIMES NO!!!
Tears or smile,
WHO KNOWS???