js 判断浏览器

function browserType(){
var type=true;
if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion .split(";")[1].replace(/[ ]/g,"")=="MSIE6.0") {
}else if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion .split(";")[1].replace(/[ ]/g,"")=="MSIE7.0") {
}else if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion .split(";")[1].replace(/[ ]/g,"")=="MSIE8.0"){
}else if(navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion .split(";")[1].replace(/[ ]/g,"")=="MSIE9.0"){
type=false;
}
return type;
}