var isIE7=(navigator.appVersion.indexOf('MSIE 7.')==-1) ? false : true;
var newImgSrc = '';
var lnkOld = '1';

function changeImg(imgSrc, lnk){
	if(lnk != null){
		document.getElementById('imgLnk_'+lnkOld).style.color='';;
		lnk.style.color='black';
		lnk.blur();
		lnkOld=lnk.innerHTML;
	}
	var newImg = new Image();
	document.getElementById('main_img').src='img/spacer.gif';
	newImgSrc = imgSrc;
	
	if(isIE7) newImg.onload=function(){imageLoaded();}
	else newImg.onload=imageLoaded;

	newImg.src = imgSrc;
	return false;
}
function imageLoaded(){
	document.getElementById('main_img').src=newImgSrc;
}