A little joke

Once there were two crazy men that were trying to scape of the psychriatic center their name were John and peter, and Peter told John that he had a plan for scaping of this center.

John asked him what he had to do, and Peter said to him look at the yard if the wall is short twe are jumping it , and if it is tall we are passing under it. John told him, man we are not able to escape, and Peter asked him why? John said because there isn't any wall over there.