String.prototype.strstr

@Description: Returns true if the substring is found in the string
@File: String/prototype/strstr.js
@Author: Paul Visco
@Version: 1.0 11/19/07
@Param: String needle The substring to search for within the string
@Return: Boolean True if the string is found and false if it isn't
@Example:

var myString = 'hello world on earth';

var answer = myString.strstr('world');
//answer = true;