Uncaught TypeError: Cannot read property 'style' of null怎么处理这个问题？
<!DOCTYPE html>
<html>
<head>
<title></title>
<style>
#my3dspace{
-webkit-perspective: 800;
-webkit-perspective-origin: 50% 50%;
overflow:hidden;
}
#pagegroup{
width:400px;
height:400px;
margin:0 auto;
-webkit-transform-style:preserve-3d;
position: relative;
}
.page{
width:360px;
height:360px;
padding:20px;
background-color: black;
color:white;
font-weight:bold;
font-size:360px;
line-height:360px;
text-align:center;
position:absolute;
}
#page1{
-webkit-transform-origin:bottom;
-webkit-transition: -webkit-transform 1s linear;
}
#page2,#page3,#page4,#page5,#page6{
-webkit-transform-origin:bottom;
-webkit-transition: -webkit-transform 1s linear;
-webkit-transform: rotateX(90deg);
}
#op{
text-align:center;
margin: 40px auto;
}
</style>
<script type="text/javascript">
var curIndex = 1;
function next(){
if( curIndex == 6 )
return;
var curPage = document.getElementById("page"+curIndex);
curPage.style.webkitTransform = "rotateX(-90deg)";
curIndex ++;
var nextPage = document.getElementById("page"+curIndex);
nextPage.style.webkitTransform = "rotateX(0deg)";
}
function prev(){
if( curIndex == 1 )
return;
var curPage = document.getElementById("page"+curIndex);
curPage.style.webkitTransform = "rotateX(90deg)";
curIndex --;
var prevPage = document.getElementById("page"+curIndex);
prevPage.style.webkitTransform = "rotateX(0deg)";
}
</script>
</head>
<body>
<div id="my3dspace">
<div id="pagegroup">
<div class="page" id="page1">1</div>
<div class="page" id="page2">2</div>
<div class="page" id="page3">3</div>
<div class="page" id="page4">4</div>
<div class="page" id="page5">5</div>
<div class="page" id="page6">6</div>
</div>
</div>
<div id="op">
<a href="javascript:next()">next</a> <a href="javascript:prev()">previous</a>
</div>
</body>
</html>
