var container = document.getElementById("container");
var list = document.getElementById("list");
var buttons = document.getElementById("buttons").getElementsByTagName("span");
var prev = document.getElementById("prev");
var next = document.getElementById("next");
var index = 1;//显示小圆点
var animated = false;
var interval=2000;
var timer;
//小圆点的切换
function animate(change){
animated=true;
var newleft=parseInt(list.style.left)+change;
var time=100;//位移总时间
var interval=50;//位移间隔时间
var speed=change/(time/interval);//每次位移量
function go(){
if((speed < 0 && parseInt(list.style.left)>newleft)||(speed > 0&&parseInt(list.style.left)<newleft)){
list.style.left=parseInt(list.style.left)+speed+"px";
setTimeout(go,interval);
}
else{
list.style.left=newleft+"px";
if(newleft>-590)
{
list.style.left= -5310+"px";
}
if(newleft<-5310)
{
list.style.left=-590+"px";
}
animated=false;
}
} go();
}
function showbutton() {
for (var i = 0; i < buttons.length ; i++) {
if( buttons[i].className == "on"){
buttons[i].className = "";
break;
}
}
buttons[index - 1].className = "on";
}
function play() {
timer = setTimeout(function () {
next.onclick();
play();
}, interval);
}
function stop() {
clearTimeout(timer);
}
//左箭头
prev.onclick=function(){
if(index==1){
index=8;
}
else{
index -=1;
}
showbutton();
if(animated==false){
animate(590);
}
}
//右箭头
next.onclick=function(){
if(index==8){
index=1;
}
else{
index +=1;
}
showbutton();
if(animated==false){
animate(-590);
}
}
//小圆点点击事件
for (var i = 0; i < buttons.length; i++) {
buttons[i].onclick = function () {
if (animated) {
return;
}
if(this.className == "on") {
return;
}
var myIndex = parseInt(this.getAttribute("index"));
var change= -590 * (myIndex - index);
animate(change);
index = myIndex;
showbutton();
}
}
container.onmouseover = stop;
container.onmouseout = play;
play();
}
</script>
一直报这个错误
Uncaught TypeError: Cannot set property 'onmouseover' of null
谢谢