ns4=(document.layers)?true:false

/** 层个数及宽高设置 开始 **/
var displayImgAmount=3	//显示窗口内同时显示的滚动层个数。注：必须恰为视区窗口可完整显示层个数+1
var divWidth=140	//每滚动层占位宽
var divHeight=85	//每滚动层占位高
/** 层个数及宽高设置 结束 **/

var startDnum=0
var nextDnum=startDnum+displayImgAmount
var timeID
var outHover=false

var startDivClipTop
var nextDivClipBottom

function initDivPlace(){
	if (ns4){
		for (i=0;i<displayImgAmount;i++){
			eval("document.divOuter.document.divAds"+i+".top="+divHeight*i)
		}
		for (i=displayImgAmount;i<imgArr.length;i++){
			eval("document.divOuter.document.divAds"+i+".top="+divHeight*displayImgAmount)
		}
	}else{
		for (i=0;i<displayImgAmount;i++){
			eval("document.all.divAds"+i+".style.top="+divHeight*i)
		}
		for (i=displayImgAmount;i<imgArr.length;i++){
			eval("document.all.divAds"+i+".style.top="+divHeight*displayImgAmount)
		}
	}
}

function mvStart(){
	timeID=setTimeout(moveLeftDiv,moveRelax)
}

function mvStop(){
	clearTimeout(timeID)
}

function moveLeftDiv(){
	if (ns4){
		for (i=0;i<=displayImgAmount;i++){
			eval("document.divOuter.document.divAds"+parseInt((startDnum+i)%imgArr.length)+".top=document.divOuter.document.divAds"+parseInt((startDnum+i)%imgArr.length)+".top-moveStep")
		}

		startDivClipTop=parseInt(eval("document.divOuter.document.divAds"+startDnum+".clip.top"))
		nextDivClipBottom=parseInt(eval("document.divOuter.document.divAds"+nextDnum+".clip.bottom"))

		if (startDivClipTop+moveStep>divHeight){
			eval("document.divOuter.document.divAds"+nextDnum+".clip.bottom="+divHeight)
			
			eval("document.divOuter.document.divAds"+startDnum+".top="+divHeight*displayImgAmount)
			eval("document.divOuter.document.divAds"+parseInt((nextDnum+1)%imgArr.length)+".top=document.divOuter.document.divAds"+nextDnum+".top+"+divHeight)
			eval("document.divOuter.document.divAds"+parseInt((nextDnum+1)%imgArr.length)+".clip.top=0")
			
			
			startDnum=(++startDnum)%imgArr.length
			nextDnum=(startDnum+displayImgAmount)%imgArr.length
			
			startDivClipTop=moveStep-(divHeight-startDivClipTop)
			nextDivClipBottom=moveStep-(divHeight-nextDivClipBottom)
		}else{
			eval("document.divOuter.document.divAds"+nextDnum+".clip.top=0")
			startDivClipTop+=moveStep
			nextDivClipBottom+=moveStep
		}
		eval("document.divOuter.document.divAds"+startDnum+".clip.top="+startDivClipTop)
		eval("document.divOuter.document.divAds"+nextDnum+".clip.bottom="+nextDivClipBottom)
	}else{
		for (i=0;i<=displayImgAmount;i++){
			eval("document.all.divAds"+parseInt((startDnum+i)%imgArr.length)+".style.top=document.all.divAds"+parseInt((startDnum+i)%imgArr.length)+".style.pixelTop-moveStep")
		}
	
		startDivClipTop=parseInt(eval("document.all.divAds"+startDnum+".currentStyle.clipTop"))
		nextDivClipBottom=parseInt(eval("document.all.divAds"+nextDnum+".currentStyle.clipBottom"))
	
		if (startDivClipTop+moveStep>divHeight){
			eval("document.all.divAds"+nextDnum+".style.clip='rect(0,"+divWidth+","+divHeight+",0"+")'")
			
			eval("document.all.divAds"+startDnum+".style.top="+divHeight*displayImgAmount)
			eval("document.all.divAds"+parseInt((nextDnum+1)%imgArr.length)+".style.top=document.all.divAds"+nextDnum+".style.pixelTop+"+divHeight)
			
			startDnum=(++startDnum)%imgArr.length
			nextDnum=(startDnum+displayImgAmount)%imgArr.length
			
			startDivClipTop=moveStep-(divHeight-startDivClipTop)
			nextDivClipBottom=moveStep-(divHeight-nextDivClipBottom)
		}else{
			startDivClipTop+=moveStep
			nextDivClipBottom+=moveStep
		}
		eval("document.all.divAds"+startDnum+".style.clip='rect("+startDivClipTop+","+divWidth+","+divHeight+",0)'")
		eval("document.all.divAds"+nextDnum+".style.clip='rect(0,"+divWidth+","+startDivClipTop+",0)'")
	}

	if (outHover){
		mvStop()
	}else{
		mvStart()
	}
	
	
}

function writeDivs(){
	if (ns4){
		document.write("<ilayer name=divOuter width=120 height=240>")
		
		for (i=0;i<imgArr.length;i++){
			document.write("<layer name=divAds"+i+">")
			document.write(imgArr[i]+" ")
			document.write("</layer>")
		}
		document.write("</ilayer>")
		document.close()
		for (i=displayImgAmount;i<imgArr.length;i++){
			eval("document.divOuter.document.divAds"+i+".clip.bottom=0")
		}
	}else{
		document.write("<div id=divOuter style='position:relative' width="+divWidth+" height=300>")
		
		for (i=0;i<imgArr.length;i++){
			document.write("<div id=divAds"+i+" style='position:absolute;clip:rect(0,"+divWidth+","+divHeight+",0)'>")
			document.write(imgArr[i]+" ")
			document.write("</div>")
		}
		document.write("</div>")
		for (i=displayImgAmount;i<imgArr.length;i++){
			eval("document.all.divAds"+i+".style.clip='rect(0,0,0,"+divWidth+")'")
		}
	}
}