//browsererkennung
var isMinNS4 = (navigator.appName.indexOf("Netscape") >= 0 && parseFloat(navigator.appVersion) >= 4&&parseFloat(navigator.appVersion) < 5) ? 1 : 0;
var isMinNS6 = (isMinNS4 && navigator.userAgent.indexOf("Gecko")>=0) ? 1 : 0;
var isMinIE4 = (document.all) ? 1 : 0;
var isMinIE5 = (isMinIE4 && navigator.appVersion.indexOf("5.")) >= 0 ? 1 : 0;
var isDOM = (document.getElementById) ? 1 : 0;
var isMac = (navigator.appVersion.indexOf("Mac",0) >= 0) ? 1 : 0;
var isOpera = (navigator.userAgent.toLowerCase().indexOf('opera') >= 0) ? 1 : 0;

	if (document.images) { 
		// preloading right images
		footer1on=new Image();
		footer1on.src="images/nav/footernav_home_on.gif";
		footer1off=new Image();
		footer1off.src="images/nav/footernav_home.gif";

		footer2on=new Image();
		footer2on.src="images/nav/footernav_kontakt_on.gif";
		footer2off=new Image();
		footer2off.src="images/nav/footernav_kontakt.gif";

		footer3on=new Image();
		footer3on.src="images/nav/footernav_impressum_on.gif";
		footer3off=new Image();
		footer3off.src="images/nav/footernav_impressum.gif";
	}
	
	// function to activate images
	function imgOn(imgName) {
		if (isDOM) {
		//alert('dom');
		document.getElementById(imgName).src = eval(imgName+"on.src");
		} else {
		//alert('nodom');
		document[imgName].src=eval(imgName+"on.src");
		}
	}
	
	// function to deactivate images
	function imgOff(imgName) {
		if (isDOM) {
		document.getElementById(imgName).src = eval(imgName+"off.src");
		} else {
		document[imgName].src=eval(imgName+"off.src");
		}
	}