var cpAD=new Array(); 
var cpADlink=new Array(); 
var cpADmsg=new Array(); 

var adNum=3; 
var coll=0;

cpAD[0]="ima/data/ad4.jpg"; 
cpADlink[0]="books/books.htm"; 
cpADmsg[0]="1"; 

cpAD[1]="ima/data/ad5.jpg"; 
cpADlink[1]="books/books.htm"; 
cpADmsg[1]="2"; 

cpAD[2]="ima/data/ad6.jpg"; 
cpADlink[2]="books/books.htm"; 
cpADmsg[2]="3"; 


var preloadedimages=new Array(); 
for (i=1;i<cpAD.length;i++){ 
preloadedimages[i]=new Image(); 
preloadedimages[i].src=cpAD[i]; 
} 

//跳转的URL地址
function jump2url()
{ 
jumpUrl=cpADlink[adNum]; 
jumpTarget='_blank'; 
if (jumpUrl != '')
{ 
	if (jumpTarget != '')
		window.open(jumpUrl,jumpTarget); 
	else location.href=jumpUrl; 
	} 
}

//图片变化的函数
function changeimg(n)
{
	adNum=n;
	switch(adNum)
	{
	case 0:
	{
		window.img1.src="ima/data/1-2.gif";
		window.img2.src="ima/data/2.gif";
		window.img3.src="ima/data/3.gif";
		break;
	}
	case 1:
	{
		window.img1.src="ima/data/1.gif";
		window.img2.src="ima/data/2-2.gif";
		window.img3.src="ima/data/3.gif";
		break;
	}
	case 2:
	{
		window.img1.src="ima/data/1.gif";
		window.img2.src="ima/data/2.gif";
		window.img3.src="ima/data/3-2.gif";
		break;
	}
	}
	window.clearInterval(theTimer);
	adNum=adNum-1;
	nextAd();
}
//当点击时直接跳转
function nextAd(){ 
coll++;
if(coll>1)
{
switch(adNum+1)
{
	case 5:
	{
		window.img1.src="ima/data/1-2.gif";
		window.img2.src="ima/data/2.gif";
		window.img3.src="ima/data/3.gif";
		break;
	}
	case 1:
	{
		window.img1.src="ima/data/1.gif";
		window.img2.src="ima/data/2-2.gif";
		window.img3.src="ima/data/3.gif";
		break;
	}
	case 2:
	{
		window.img1.src="ima/data/1.gif";
		window.img2.src="ima/data/2.gif";
		window.img3.src="ima/data/3-2.gif";
		break;
	}
}
}
if(adNum<cpAD.length-1)adNum++ ; 
else adNum=0; 
setTransition(); 
document.images.cpADrush.src=cpAD[adNum]; 
playTransition(); 
displayStatusMsg();
//定义了轮换时间 5s
theTimer=setTimeout("nextAd()", 5000); 
} 

function setTransition(){ 
if (document.all){ 
cpADrush.filters.revealTrans.Transition=23; 
cpADrush.filters.revealTrans.apply(); 
} 

} 
function playTransition(){ 
if (document.all) 
cpADrush.filters.revealTrans.play() 
} 
function displayStatusMsg() { 
status=cpADmsg[adNum]; 
document.returnValue = true; 
}