var which='';
var active_1 = '';
var active_2 = '';
var active_3 = '';

var label_1_src = 'img/label_1.gif';
var label_2_src = 'img/label_2.gif';
var label_3_src = 'img/label_3.gif';


function setActive(nav_1,nav_2,nav_3){
	
	active_1=nav_1;
	active_2=nav_2;
	active_3=nav_3;
	
	if (navigator.appName=='Netscape' && navigator.appVersion.charAt(0)<'5') 
	{
		if (document.navigation.document.images) {
			
			if(nav_1!='')
				document.navigation.document.images[nav_1].src=label_1_src;
				
			if(nav_2!='')
				document.navigation.document.images[nav_2].src=label_2_src;
				
			if(nav_3!='')
				document.navigation.document.images[nav_3].src=label_3_src;
				
			return true;
		}
		else return false;
	}
	else
	{
		if (document.images) {
			
			if(nav_1!='')
				document.images[nav_1].src=label_1_src;
			if(nav_2!='')
				document.images[nav_2].src=label_2_src;
			if(nav_3!='')
				document.images[nav_3].src=label_3_src;
				
			return true;
		}
		else return false;
	}
	
}


// hilight images
function swop(whichButton,toButton) {
	
	if(!(whichButton==active_1 || whichButton==active_2 || whichButton==active_3))
	{
		// swop
		if (navigator.appName=='Netscape' && navigator.appVersion.charAt(0)<'5') {
			if (document.navigation.document.images) {
				document.navigation.document.images[whichButton].src=toButton;
				return true;
			}
			else return false;
		}
		else
		{
			if (document.images) {
				document.images[whichButton].src=toButton;
				return true;
			}
			else return false;
		}
	}
}

// open new window
function oeffneFenster(seitenName,instanzName,fensterBreite,fensterHoehe) {
	breiteBildschirm = screen.availWidth;
	hoeheBildschirm = screen.availHeight - 20;
	randLinks = breiteBildschirm/2-(fensterBreite/2);
	randOben = hoeheBildschirm/2-(fensterHoehe/2);
	fensterParameter = "top="+randOben+",left="+randLinks+",width="+fensterBreite+",height="+fensterHoehe+",scrollbars=no,toolbar=no,status=no,resizeable=no,location=no";
	satellitenFenster = window.open(seitenName,instanzName,fensterParameter);
	satellitenFenster.focus();
}