? <script>
???
? var loadtime=30*60*1000;
? function millisecondToDate(msd){
??? var time = parseFloat(msd) / 1000;

??????? if (time > 60 && time < 60 * 60){
??????????? time = parseInt(time / 60.0) + "分钟" + parseInt(time % 60.0)? + "秒";
??????? }
??????? else if (time >= 60 * 60 && time < 60 * 60 * 24){
??????????? time = parseInt(time / 3600.0) + "小时" + parseInt(time / 60.0)+ "分钟" +parseInt(time % 60.0) + "秒";
??????? }
??????? else{
??????????? time = parseInt(time) + "秒";
??????? }
???
??? return time;
}

?? //加载倒计时
??????? function initNumLoad(){
????? var time;
??????????? loadtime=loadtime-1000;
??????????? if(loadtime < 0){
?????????????? clearInterval(interval_id);
??????????? }else{
???? time=millisecondToDate(loadtime);
???? alert(time);
??????????? }
???????????
??????? }
?????
?? function check(){
????? interval_id=setInterval(initNumLoad, 1000);//循环调用
?? }

? </script>