function openHelp() {

	w = 800;
	h = 600;
	w = screen.availWidth;
	h = screen.availHeight;
	popW = 480;
	popH = 445;
	leftPos = (w-popW)/2;
	topPos = ((h-popH)/2) * 0.75;

	window.open('help.htm','help','width=' + popW + ',height=' + popH + ',top=' + topPos + ',left=' + leftPos);

}