shuffle 배열섞기

function shuffle(arr) {

for (var x=0; x< arr.length*2; x++) {

var i = parseInt(Math.random()*arr.length);

var j = parseInt(Math.random()*arr.length);

var tmp = arr[i];  arr[i] = arr[j]; arr[j] = tmp;

}

return arr;

}

original = [1,2,3,4,5,6,7,8,9];

result = shuffle(original);

document.write(result);