js之判断浏览器类型及版本号

function browserinfo(){
        var Browser_Name=navigator.appName;
        var Browser_Version=parseFloat(navigator.appVersion);
        var Browser_Agent=navigator.userAgent;
        
        var Actual_Version,Actual_Name;
        
        var is_IE=(Browser_Name=="Microsoft Internet Explorer");
        var is_NN=(Browser_Name=="Netscape");
        
        if(is_NN){
            //upper 5.0 need to be process,lower 5.0 return directly
            if(Browser_Version>=5.0){
                var Split_Sign=Browser_Agent.lastIndexOf("/");
                var Version=Browser_Agent.indexOf(" ",Split_Sign);
                var Bname=Browser_Agent.lastIndexOf(" ",Split_Sign);

                 Actual_Version=Browser_Agent.substring(Split_Sign+1,Version);
                 Actual_Name=Browser_Agent.substring(Bname+1,Split_Sign);
             }
            else{
                 Actual_Version=Browser_Version;
                 Actual_Name=Browser_Name;
             }
         }
        else if(is_IE){
            var Version_Start=Browser_Agent.indexOf("MSIE");
            var Version_End=Browser_Agent.indexOf(";",Version_Start);
             Actual_Version=Browser_Agent.substring(Version_Start+5,Version_End)
             Actual_Name=Browser_Name;
            
            if(Browser_Agent.indexOf("Maxthon")!=-1){
                 Actual_Name+="(Maxthon)";
             }
            else if(Browser_Agent.indexOf("Opera")!=-1){
                 Actual_Name="Opera";
                var tempstart=Browser_Agent.indexOf("Opera");
                var tempend=Browser_Agent.length;
                 Actual_Version=Browser_Agent.substring(tempstart+6,tempend)
             }
         }
        else{
             Actual_Name="Unknown Navigator"
             Actual_Version="Unknown Version"
         }
        /*------------------------------------------------------------------------------
         --Your Can Create new properties of navigator(Acutal_Name and Actual_Version) --
         --Userage:                                                                     --
         --1,Call This Function.                                                        --
         --2,use the property Like This:navigator.Actual_Name/navigator.Actual_Version;--
         ------------------------------------------------------------------------------*/
         navigator.Actual_Name=Actual_Name;
         navigator.Actual_Version=Actual_Version;
        
        /*---------------------------------------------------------------------------
         --Or Made this a Class.                                                     --
         --Userage:                                                                  --
         --1,Create a instance of this object like this:var browser=new browserinfo;--
         --2,user this instance:browser.Version/browser.Name;                        --
         ---------------------------------------------------------------------------*/
        this.Name=Actual_Name;
        this.Version=Actual_Version;
     }
     browserinfo();
    
     document.write("你使用的浏览器是:"+navigator.Actual_Name+",版本号:"+navigator.Actual_Version);