array.contains.js

Array.prototype.each = function(callback) {
    var i = this.length, j = 0;

    while(i--) {
        callback.call(this, this[j++]);
    }
};

Array.prototype.contains = function(needle) {
    var contains = false;

    this.each(function(val) {
	if(needle === val) contains = true;
    });
    
    return contains;
}