var alldataarr = alldata.split(",")
var num = alldataarr.length-1
var timer
function change(){
document.getElementById("oknum").value = alldataarr[GetRnd(0,num)];
}
function start(){
clearInterval(timer);
timer = setInterval('change()',50); //50(毫秒)为变换间隔,越小变换的越快
}