为什么我这里按钮切换没有用
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<html>
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<div class="clear"></div>
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<div class="clear"></div>
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<div class="arrow prev"><</div>
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<script>
window.onload=function(){
var swiper=document.getElementsByClassName("swiper");
var container=document.getElementsByClassName("container");
var slide=document.getElementsByClassName("slide");
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var prev=document.getElementsByClassName("prev");
var next=document.getElementsByClassName("next");
function animate(offset){
container.style.left=parseInt(container.style.left)+offset+"px";
};
prev.onclick=function(){
animate(600);
};
next.onclick=function(){
animate(-600);
}
}
</script>
</body>
</html>
