var x, y, obj, down = false;

function mouseDown() {
	obj = event.srcElement;
	obj.setCapture();
	x = event.offsetX;
	y = event.offsetY;
	down = true;
}

function mouseMove() {
	if(down == true && event.srcElement == obj) {
		with(obj.parentElement.style) {
			posLeft = event.x - x + document.body.scrollLeft;
			posTop = event.y - y + document.body.scrollTop;
		}
	}
}

function mouseUp() {
	down = false;
	obj.releaseCapture();
}