function getLayerRefMoveLayer(layerName) {
	var layerRef = (document.getElementById) ? document.getElementById(layerName).style : (document.all) ? document.all[layerName].style : (document.layers) ? document[layerName] : 0;
	return layerRef;
}

function moveLayerYB(layerName,y) { //moves layer to abs y-coords
	if (y != null) getLayerRefMoveLayer(layerName).bottom = y;
}

function moveLayerYT(layerName,y) { //moves layer to abs y-coords
	if (y != null) getLayerRefMoveLayer(layerName).top = y;
}