function showCredits() {
	var box = $("#credits_box");
	
	var boxSize = { width: box.width(), height: box.height() };
	var winsize = { width: $(window).width(), height: $(document.body).height() };
	
	//if(/MSIE/.test(navigator.userAgent)) alert("IE");
	
	box.css({
		position: 'absolute',
		top: (winsize.height - boxSize.height)/2 + 20, 
		left: (winsize.width - boxSize.width)/2 
	}); 
	
	box.show('slow');
}

function hideCredits() {
	$("#credits_box").hide('slow');
}