function leftqiehuan(num){
if(num==1){
document.getElementById("mylist"+num).className="list0";
document.getElementById("mylist"+2).className="list1";
document.getElementById("mylist"+3).className="list1";
document.getElementById("mylist"+4).className="list1";
}else if(num==2){
document.getElementById("mylist"+num).className="list0";
document.getElementById("mylist"+1).className="list1";
document.getElementById("mylist"+3).className="list1";
document.getElementById("mylist"+4).className="list1";
reinitIframe();
window.setInterval("reinitIframe()", 200);
}else if(num==3){
document.getElementById("mylist"+num).className="list0";
document.getElementById("mylist"+1).className="list1";
document.getElementById("mylist"+2).className="list1";
document.getElementById("mylist"+4).className="list1";
reinitIframe();
}else{
document.getElementById("mylist"+num).className="list0";
document.getElementById("mylist"+1).className="list1";
document.getElementById("mylist"+2).className="list1";
document.getElementById("mylist"+3).className="list1";
reinitIframe();
}
}