Smile though your heart is aching
Smile even though it's breaking
When there are clouds in the sky
You'll get by
If you smile through your fear and sorrow
Smile and maybe tomorrow
You'll see the sun come shining through
Light up your face with gladness
Hide every trace of sadness
Although a tear
May be ever so near
That's the time you must keep on tryin'
Smile, what's the use of cryin'
You'll find that life is still worthwhile
If you'd just smile
Lyrics taken from http://www.lyricsmode.com/lyrics/e/elvis_costello/smile_lyrics.html