将数组元素的顺序打乱

var arr:Array = [1,1,2,2,3,3,4,4,5,5,6,6];
disorder(arr);
trace(arr);
function disorder(arr : Array):Array
{
    var len:uint = arr.length;
    var cache:*,ti:uint;
    for (var i : uint = 0; i < len; i++)
    {
        ti = int(Math.random() * len);
        cache = arr[i];
        arr[i] = arr[ti];
        arr[ti] = cache;
    }
    while (--i >= 0)
    {
        ti = int(Math.random() * len);
        cache = arr[i];
        arr[i] = arr[ti];
        arr[ti] = cache;
    }
    return arr;
}