function calculateBgX(oElement) {
	return document.body.scrollLeft - getOffsetLeft(oElement);
}
function calculateBgY(oElement) {
	return document.body.scrollTop - getOffsetTop(oElement);
}

function getOffsetTop(oElement) {
	var iResult= oElement.offsetTop;
	while (oElement.offsetParent) {
		oElement = oElement.offsetParent;
		iResult += oElement.offsetTop;
	}
	return iResult;
}
function getOffsetLeft(oElement) {
	var iResult= oElement.offsetLeft;
	while (oElement.offsetParent) {
		oElement = oElement.offsetParent;
		iResult += oElement.offsetLeft;
	}
	return iResult;
}