buttonDir = "/images/";
	
	// preload buttons
	if (document.images) {
		buttons = new Array ("bu-getInfo", "bu-getInfoShow", "bu-go", "bu-infoListen", "bu-listen", "bu-discuss");
		buttonImage = new Array();
		for (i=0; i < buttons.length; i++) {
			buttonImage[i] = new Image();
			buttonImage[i].src = buttonDir + buttons[i] + "-on.gif";
		}
	}