function showNavOptions(optionName){
	if (document.layers){
		document.none.visibility = "hidden";
		document.home.visibility = "hidden";
		document.pci.visibility = "hidden";
		document.baan.visibility = "hidden";
		document.contact.visibility = "hidden";
		document.werken.visibility = "hidden";
		document.profiel.visibility = "hidden";
		document.eval(optionName).visibility = "visible";
	} 
	else if (document.getElementById){
		document.getElementById('home').style.visibility = "hidden";
		document.getElementById('pci').style.visibility = "hidden";
		document.getElementById('baan').style.visibility = "hidden";
		document.getElementById('contact').style.visibility = "hidden";
		document.getElementById('werken').style.visibility = "hidden";
		document.getElementById('profiel').style.visibility = "hidden";
		document.getElementById(optionName).style.visibility = "visible";
		}
	}
	
	if (document.images) {
	nav_home = new Image();
	nav_home.src = "gfx/menu3/off1.gif";
	nav_homeover = new Image();
	nav_homeover.src = "gfx/menu3/on1.gif";
	
	nav_pci = new Image();
	nav_pci.src = "gfx/menu3/off2.gif";
	nav_pciover = new Image();
	nav_pciover.src = "gfx/menu3/on2.gif";
	
	nav_baan = new Image();
	nav_baan.src = "gfx/menu3/off6.gif";
	nav_baanover = new Image();
	nav_baanover.src = "gfx/menu3/on6.gif";
	
	nav_contact = new Image();
	nav_contact.src = "gfx/menu3/off3.gif";
	nav_contactover = new Image();
	nav_contactover.src = "gfx/menu3/on3.gif";
	
	nav_werken = new Image();
	nav_werken.src = "gfx/menu3/off5.gif";
	nav_werkenover = new Image();
	nav_werkenover.src = "gfx/menu3/on5.gif";
	
	nav_profiel = new Image();
	nav_profiel.src = "gfx/menu3/off4.gif";
	nav_profielover = new Image();
	nav_profielover.src = "gfx/menu3/on4.gif";
	}
	
	
	function swapOn(imgName) {
	
	if (document.images) {
	eval("document." + imgName + ".src = " + imgName + "over.src");
	}
}
	
	function swapOff(imgName) {
	if (document.images) {
	eval("document." + imgName + ".src = " + imgName + ".src");
	}
}
	
	function nav_swapOn(imgName) {
	if (document.images) {
	eval("document." + 'sub_nav' + ".src = " + imgName + "over.src");
	}
}