用javascript一個判斷瀏覽器類型

用javascript一個判斷瀏覽器類型,下面的可以在FF和IE中可以判斷,但是在Opera和Maxthon沒有判斷出來,不知道是哪個地方出錯了,我用的是opera 9.52的,maxthon 2.1.3的都沒有給判斷出來,有誰知道,可以看看是哪個地方出錯了呢?

<script type="text/javascript">

    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"

        }

 

        navigator.Actual_Name=Actual_Name;

        navigator.Actual_Version=Actual_Version;         

 

        this.Name=Actual_Name;

        this.Version=Actual_Version;

    }

    browserinfo();

    

    document.write("你使用的瀏覽器是:"+navigator.Actual_Name+",版本號碼:"+navigator.Actual_Version);

</script>