if(window.navigator.userAgent.toLowerCase().indexOf("msie") > 0){

    return “IE”;

}

if(window.navigator.userAgent.toLowerCase().indexOf("msie 8.0") > -1){

    return “IE 8”;

}

firefox判断应该是ua.match(/firefox[\/\s](\d+)/);

 

var isIE=!!window.ActiveXObject; 

var isIE6=isIE&&!window.XMLHttpRequest; 

var isIE8=isIE&&!!document.documentMode; 

var isIE7=isIE&&!isIE6&&!isIE8; 

if (isIE){ 

if (isIE6){ 

alert("ie6"); 

}else if (isIE8){ 

alert("ie8"); 

}else if (isIE7){ 

alert("ie7"); 

} 

} 

 

f(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion.match(/6./i)=="6."){ 

alert("IE 6"); 

} 

else if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion.match(/7./i)=="7."){ 

alert("IE 7"); 

} 

else if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion.match(/8./i)=="8."){ 

alert("IE 8"); 

} 

else if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion.match(/9./i)=="9."){ 

alert("IE 9"); 

} 

 

 

if(navigator.userAgent.indexOf("Opera") != -1) { 

alert('Opera'); 

} 

else if(navigator.userAgent.indexOf("MSIE") != -1) { 

alert('Internet Explorer'); 

} 

else if(navigator.userAgent.indexOf("Firefox") != -1) { 

alert('Firefox'); 

} 

else if(navigator.userAgent.indexOf("Netscape") != -1) { 

alert('Netscape'); 

} 

else if(navigator.userAgent.indexOf("Safari") != -1) { 

alert('Safari'); 

} 

else{ 

alert('无法识别的浏览器。'); 

}