Determine the browser type and version number based on JS

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 ("your browser is:" + navigator. actual_name + ", version:" + navigator. actual_version );