var homeon = new Image();
	var abouton = new Image();
	var newson = new Image();
	var resourceson = new Image();
	var contact_uson = new Image();
	var pdi_projecton = new Image();
	var contributorson = new Image();
	var uqgon = new Image();
	var phon = new Image();
	var iron = new Image();
	var homeoff = new Image();
	var aboutoff = new Image();
	var newsoff = new Image();
	var resourcesoff = new Image();
	var contact_usoff = new Image();
	var pdi_projectoff = new Image();
	var contributorsoff = new Image();
	var uqgoff = new Image();
	var phoff = new Image();
	var iroff = new Image();

	homeon.src = "/images/home-2_on.gif";
	abouton.src = "/images/about-2_on.gif";
	newson.src = "/images/news-2_on.gif";
	resourceson.src = "/images/resources-2_on.gif";
	contact_uson.src = "/images/contact-2_on.gif";
	pdi_projecton.src = "/images/pdi_project-2_on.gif";
	contributorson.src = "/images/contributors-2_on.gif";
	homeoff.src = "/images/home-2_off.gif";
	aboutoff.src = "/images/about-2_off.gif";
	newsoff.src = "/images/news-2_off.gif";
	resourcesoff.src = "/images/resources-2_off.gif";
	contact_usoff.src = "/images/contact-2_off.gif";
	pdi_projectoff.src = "/images/pdi_project-2_off.gif";
	contributorsoff.src = "/images/contributors-2_off.gif";

	uqgon.src = "/guidelines/images/uqg_button_on.gif";
	phon.src = "/guidelines/images/ph_button_on.gif";
	iron.src = "/guidelines/images/ir_button_on.gif";
	uqgoff.src = "/guidelines/images/uqg_button_off.gif";
	phoff.src = "/guidelines/images/ph_button_off.gif";
	iroff.src = "/guidelines/images/ir_button_off.gif";

	// Activate image.
	function imgAct(imgName)
	{
		document[imgName].src = eval(imgName + "on.src");
	}

	// Deactivate image.
	function imgInact(imgName)
	{
		document[imgName].src = eval(imgName + "off.src");
	}

	// Popup window.
	function openNewWindow(strURL)
	{
		popupWin = window.open(strURL, 'open_window', 'menubar, toolbar, location, directories, status, scrollbars, resizable, dependent, width=640, height=480, left=0, top=0');
	}