var RolloverPreImg=new Array();
var RolloverOutSrc=new Array();
var RolloverPostfix='_f2';

function getImgId(iImg){
	return iImg.src.replace(RolloverPostfix+'.','.');	
}

function getOverUrl(iUrl){
	var outStr=iUrl.substr(0,iUrl.lastIndexOf('.'));
	var ext=iUrl.substr(iUrl.lastIndexOf('.'));
	outStr+=RolloverPostfix;
	outStr+=ext;
	return outStr;
	
}

function rolloverImg(iImg,iStatus){
	if(iStatus==0)
		iImg.src=RolloverOutSrc[getImgId(iImg)];
	else
		iImg.src=RolloverPreImg[getImgId(iImg)].src;
}


function initAutoRollover(){
	var imgs=document.getElementsByTagName('img');
	for (var i=0; i<imgs.length; i++){
		var curImg=imgs[i];
		if(curImg.className!='auto_rollover') continue;
		RolloverPreImg[getImgId(curImg)]=new Image();
		RolloverOutSrc[getImgId(curImg)]=curImg.src;
		RolloverPreImg[getImgId(curImg)].src=getOverUrl(curImg.src);
		curImg.onmouseout=function(){rolloverImg(this,0)};
		curImg.onmouseover=function(){rolloverImg(this,1)};
	}
}