从n个数中随机选出m个

//by trickman
function numberGo() {
Array.prototype.shuffle = function() {
var len = this.length;
for (var i = 0; i<len; i++) {
var rand = Math.floor(Math.random()*len);
var temp = this[i];
this[i] = this[rand];
this[rand] = temp;
}
};
//以上是用来打乱数字顺序的函数。
allNumber = new Array();
totalImgs = 12;
for (i=0; i<totalImgs; i++) {
allNumber[i] = i+1;
}
//以上创建一个数组，包含1到12，12个数字。
allNumber.shuffle();
//调用函数,打乱数字顺序
luckyNumber1 = allNumber[0];
luckyNumber2 = allNumber[1];
luckyNumber3 = allNumber[2];
//取被打乱顺序后的数组的前3个数，即所需的随机数。
trace("luckyNumber1 is " add luckyNumber1);
trace("luckyNumber2 is " add luckyNumber2);
trace("luckyNumber3 is " add luckyNumber3);
}