<!--

                 &lt:HTML字符转义，代表"<"

                 &gt:HTML字符转义，代表">"

-->

<a href="javascript:;" id="prev" class="arrow">&lt;</a>

<a href="javascript:;" id="next" class="arrow">&gt;</a>

css部分：

.arrow{

width: 30px;

height: 30px;

background-color: rgba(0,0,0,0.3);

cursor: pointer;

/*opacity: 0.6;*/

color: #FFFFFF;

text-align: center;

line-height: 30px;

font-size: 16px;

}

#prev{

position: absolute;

top: 40%;

left:5px;

}

#next{

position: absolute;

top: 40%;

right:5px;

}

js部分：

var prev=document.getElementById("prev");

var next=document.getElementById("next");

prev.onclick=function(){

index--;

if(index<0){

index=4;

}

        change(index);

        if(timer){

        clearInterval(timer);

        timer=null;

        }

        timer=setInterval(autoPlay,2000);

}

next.onclick=function(){

index++;

if(index>4){

index=0;

}

change(index);

if(timer){

        clearInterval(timer);

        timer=null;

        }

        timer=setInterval(autoPlay,2000);

}