var arrPreloadImg = new Array();

function preloadImg(strImage)
{
	var i = arrPreloadImg.length;
	arrPreloadImg[i] = new Image();
	arrPreloadImg[i].src = strImage;
}

function rover(obj, strImage)
{
	var sOld = obj.src;
	obj.src = sOld.substring(0, sOld.lastIndexOf('/')+1) + strImage;
}