function openCentered(url, name, params, popW, popH) {
	screenW = screen.width;
	screenH = screen.height;

	popL = (screenW / 2) - (popW / 2) - 8;
	popT = (screenH / 2) - (popH / 2) - 20;

	params = params + ",left=" + popL + ",top=" + popT + ",width=" + popW + ",height=" + popH;

	window.open(url, name, params);
}