function preloadImages(images)
{
	var img = new Image();
	for(i = 0; i < images.length; i++)
	{
		img.src = images[i];
	}
}

function switchImage(imgSrc, element)
{
	var el = document.getElementById(element);
	if(el)
	{
		el.src = imgSrc;
	}
	else
	{
		alert('element not found');
	}
}