var isNav4 = false;
var isW3C = false;
var isIE = false;
var isOP = false;

if (navigator.appName.indexOf("Netscape") != -1) {
	if(navigator.userAgent.indexOf("Safari") != -1){
		isOP = true; // Safari
	}else if (parseInt(navigator.appVersion) == 4) { 
		isNav4 = true; // Netscape Communicator 4.x
	} else if (parseInt(navigator.appVersion) >= 5) { 
		isW3C = true; // Netscape 6 oder Mozilla 
	}
} else { 
	if ((parseInt(navigator.appVersion) >= 4) && (navigator.appName.indexOf("Microsoft") != -1)) { 
		isIE = true; // MSIE 4.x oder hoeher
	}else if (navigator.userAgent.indexOf("Opera") != -1){ 
		isOP = true; // Opera 5.x 
	}
}

//alert(navigator.appName);
//alert(navigator.userAgent);
//alert(isNav4+" "+isW3C+" "+isIE+" "+isOP);