function swapImage(str_imgName, str_newSrc, str_layerName){
	//str_layerName = null;
	if(str_layerName==null){
		document.images[str_imgName].src = str_newSrc;
	}

	else{
		if(is.old)
			return;
		if(is.ns)
			document.images[str_imgName].src = str_newSrc;
		else if(is.ie || is.ns6)
			document.images[str_imgName].src = str_newSrc;
	}
	
}