A smile can over a mile.This is said to cheer up a sad person.This phase is actually true because many times when we are depressed a smile on the face of a small child can make us life.Doctor recommend Laughter therepy.A smile has a lots of power because a smile streches many muscles of our mind and body.We can actually defeat stress and tension with our powerful mind because when we smile then we are regressing ourselves and releasing toxins from our body