JS图片切换脚本

<script language =javascript > 

var curIndex=0;  

var arr=new Array(); //把图片的URL都放在数组中

arr[0]="1.jpg"; 

arr[1]="2.jpg"; 

arr[2]="3.jpg"; 

arr[3]="4.jpg"; 

arr[4]="5.jpg"; 

function next() { 

var obj=document.getElementById("showpic"); 

curIndex+=1; 

if(curIndex>arr.length-1){

alert("the last");

curIndex=arr.length-1;

}else{

obj.src="image/"+arr[curIndex]; 

}

} 

 

function pre(){

var obj=document.getElementById("showpic"); 

curIndex-=1; 

if(curIndex<0){

alert("the first");

curIndex=0;

}else{

obj.src="image/"+arr[curIndex]; 

}

}

</script> 

<img src="image/1.jpg" width="1000" height="800" id="showpic" /> 

<button onclick="pre();">pre</button>

<button onclick="next();">next</button>