帮我修改下图片滚动的特性

Question

<style>
#return_left,
#colee_right{ float:left;}
#return_left,
#return_right{ height:100px; line-height:100px;}
</style><div id="return_left">向左</div>
<div id="colee_right" style="overflow:auto;width:300px; height:100px;">
<div class="pic" style="width:800px;">
        <div id="colee_right1">
            <img src="image/person1.jpg">
            <img src="image/person2.jpg">
            <img src="image/person3.jpg">
            <img src="image/person4.jpg">
        </div>
        <div id="colee_right2"></div>
    </div>
</div>
<div id="return_right">向右</div>
<script>
//使用div时，请保证colee_left2与colee_left1是在同一行上.
var speed=2//速度数值越大速度越慢
var colee_right=document.getElementById("colee_right");
var colee_right1=document.getElementById("colee_right1");
var colee_right2=document.getElementById("colee_right2");
colee_right2.innerHTML=colee_right1.innerHTML
function Marquee3(){
if(colee_right.scrollLeft <=0)//offsetWidth 是对象的可见宽度
colee_right.scrollLeft=colee_right1.offsetWidth//scrollWidth 是对象的实际内容的宽，不包边线宽度
else{
colee_right.scrollLeft--;
}
}
function Marquee4(){
if( colee_right.scrollLeft >= colee_right1.offsetWidth)//offsetWidth 是对象的可见宽度
colee_right.scrollLeft=0//scrollWidth 是对象的实际内容的宽，不包边线宽度
else{
colee_right.scrollLeft++;
}
}
var MyMar3=setInterval(Marquee3,speed);
colee_right.onmouseover=function() {clearInterval(MyMar3)}
colee_right.onmouseout=function() {MyMar3=setInterval(Marquee3,speed)}
var return_left = document.getElementById("return_left");
var return_right = document.getElementById("return_right");
return_left.onclick = function(){

colee_right.scrollLeft-=50;
if(colee_right.scrollLeft <=0){
colee_right.scrollLeft =colee_right1.offsetWidth;
}
}
return_right.onclick = function(){
colee_right.scrollLeft+=50;
if(colee_right.scrollLeft >= colee_right1.offsetWidth){
colee_right.scrollLeft =0;
}
}</script>
<!--向左滚动代码结束-->
代码如上 其中函数Marquee3是向右 函数Marquee4向左。  怎么在点击左右时执行不同的函数我不会 求大手教下。现在只能单向滚动

Answer 1

var return_left = document.getElementById("return_left");
var return_right = document.getElementById("return_right");
return_left.onclick = function(){
    
        colee_right.scrollLeft-=50;
    if(colee_right.scrollLeft <=0){
        colee_right.scrollLeft =colee_right1.offsetWidth;
    }
}
return_right.onclick = function(){
    colee_right.scrollLeft+=50;
    if(colee_right.scrollLeft >= colee_right1.offsetWidth){
        colee_right.scrollLeft =0;
    }
}
这是你写的吗?

Answer 2

该这段
return_left.onclick = function(){
    clearInterval(MyMar3);
    MyMar3=setInterval(Marquee3,speed) ;  
    colee_right.onmouseout=function() {MyMar3=setInterval(Marquee3,speed)} 
}
return_right.onclick = function(){
   clearInterval(MyMar3);
   MyMar3=setInterval(Marquee4,speed) ;
   colee_right.onmouseout=function() {MyMar3=setInterval(Marquee4,speed)} 
}