Array.prototype.shuffle.js

Array.prototype.shuffle = function() {
	var i = this.length, // array length to determine current index in loop
		r, // random index value
		p; // current index value
	
	// Loop through array indicies
	while ( i-- ) {
		// always returns less than the index to ensure it always exists
		r = Math.floor( Math.random() * i );
		
		// set current value var
		p = this[i];
		
		// Swap current index value with the random index value
		this[i] = this[r];
		this[r] = p;
	}
	return this;
};