var i=1;
 if(document.images) {
    navson = new Array();
	navsoff = new Array();	
	for (i=1;i<=6;i++) {
		navson[i] = new Image();
		navson[i].src = "/images/nav_" + i + "_rollover.png";
		navsoff[i] = new Image();
		navsoff[i].src = "/images/nav_" + i + ".png";		
	}	
}

function pretoggle() {
	for (i=1;i<=6;i++) {
		if(i==1) {
			document.getElementById('topsubnav'+i).style.display = '';
		}else{
			document.getElementById('topsubnav'+i).style.display = 'none';
		}
	}
}

function toggledisplay(el){
	var i=1;
	for (i=1;i<=6;i++) 
	{
		if(el=='imgnav'+i) {
			document.getElementById('topsubnav'+i).style.display = '';
			if(document.images) {
    			document.images[el].src = navson[i].src;
    		}
		}else{
			document.getElementById('topsubnav'+i).style.display = "none";
			if(document.images) {
    			document.images['imgnav'+i].src = navsoff[i].src;
    		}
		}			
	}
}