js判断浏览器的比较全的代码_基础知识

<script> <BR><!-- <BR>function browserSniffer(netscape4URL,explorer4URL,webtvURL, <BR>aolURL,operaURL,version3URL,w3cURL) { <BR>var agt=navigator.userAgent.toLowerCase(); <BR>var agt=navigator.userAgent.toLowerCase(); <BR>var is_major = parseInt(navigator.appVersion); <BR>var is_minor = parseFloat(navigator.appVersion); <BR>var is_nav = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1) <BR>&& (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1) <BR>&& (agt.indexOf('webtv')==-1)); <BR>var is_nav2 = (is_nav && (is_major == 2)); <BR>var is_nav3 = (is_nav && (is_major == 3)); <BR>var is_nav4 = (is_nav && (is_major == 4)); <BR>var is_nav4up = (is_nav && (is_major >= 4)); <BR>var is_navonly = (is_nav && ((agt.indexOf(";nav") != -1) || <BR>(agt.indexOf("; nav") != -1)) ); <BR>var is_nav5 = (is_nav && (is_major == 5)); <BR>var is_nav5up = (is_nav && (is_major >= 5)); <BR>var is_ie = (agt.indexOf("msie") != -1); <BR>var is_ie3 = (is_ie && (is_major < 4)); <BR>var is_ie4 = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")==-1) ); <BR>var is_ie4up = (is_ie && (is_major >= 4)); <BR>var is_ie5 = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")!=-1) ); <BR>var is_ie5up = (is_ie && !is_ie3 && !is_ie4); <BR>var is_aol = (agt.indexOf("aol") != -1); <BR>var is_aol3 = (is_aol && is_ie3); <BR>var is_aol4 = (is_aol && is_ie4); <BR>var is_opera = (agt.indexOf("opera") != -1); <BR>var is_webtv = (agt.indexOf("webtv") != -1); <BR>if (is_nav4up) { <BR>location.href = netscape4URL; // netscape 4+ but not NS5 <BR>}else if (is_ie4up) { //IE4 & IE5 but returns IE4 <BR>location.href = explorer4URL; <BR>}else if (is_webtv) { // Web TV <BR>location.href = webtvURL; <BR>}else if (is_aol || is_aol3 || is_aol4) { //AOL <BR>location.href = aolURL; <BR>}else if (is_opera) { // Opera <BR>location.href = operaURL; <BR>}else if (is_ie3||is_nav3) { // 3.0 version browsers <BR>location.href = version3URL; <BR>}else if (is_nav5up) { // Netscape 5 <BR>location.href = w3cURL; <BR>} <BR>} <BR>//--> <BR></script>