if(navigator.userAgent.indexOf("MSIE 7") != -1) 
var navigateur="Internet Explorer 7";
else if(navigator.userAgent.indexOf("MSIE 6") != -1) 
var navigateur="Internet Explorer 6";
else if(navigator.userAgent.indexOf("Firefox/2") != -1) 
var navigateur="Firefox 2";
else if(navigator.userAgent.indexOf("Firefox") != -1) 
var navigateur="Firefox";
else if(navigator.userAgent.indexOf("Netscape/7") != -1) 
var navigateur="Netscape 7";
else if(navigator.userAgent.indexOf("Netscape") != -1) 
var navigateur="Netscape";
else if(navigator.userAgent.indexOf("Opera/9") != -1) 
var navigateur="Opera 9";
else if(navigator.userAgent.indexOf("Opera") != -1) 
var navigateur="Opera";
else 
var navigateur="Undefined Explorer";
document.write(navigateur);