如何用JavaScript检测是否安装了JAVA虚拟机？同时要检测虚拟机的版本？针对版本的检测主要是检测哪里可以判断不同版本？

<html> <head> <title>Javascript检测Java虚拟机及版本的代码</title><script language="JavaScript"> var javawsInstalled = 0; var javaws142Installed=0; var javaws150Installed=0; isIE = "false"; if (navigator.mimeTypes && navigator.mimeTypes.length) { x = navigator.mimeTypes['application/x-java-jnlp-file']; if (x) { javawsInstalled = 1; javaws142Installed=1; javaws150Installed=1; } } else { isIE = "true"; try { var java = new ActiveXObject("JavaWebStart.isInstalled"); // var java15 = new ActiveXObject("JavaWebStart.isInstalled.1.5.0.0");//1.5版本 if(java) { alert('已安装Java虚拟机'); } else { alert('未安装Java虚拟机'); } } catch(ex) { alert('未安装Java虚拟机'); } } </script> </head> </html> <html> <head> <script language="JavaScript"> var javawsInstalled = 0; var javaws142Installed=0; var javaws150Installed=0; isIE = "false"; if (navigator.mimeTypes && navigator.mimeTypes.length) { x = navigator.mimeTypes['application/x-java-jnlp-file']; if (x) { javawsInstalled = 1; javaws142Installed=1; javaws150Installed=1; } } else { isIE = "true"; try { var java = new ActiveXObject("JavaWebStart.isInstalled"); // var java15 = new ActiveXObject("JavaWebStart.isInstalled.1.5.0.0");//1.5版本 if(java) { alert('已安装Java虚拟机'); } else { alert('未安装Java虚拟机'); } } catch(ex) { alert('未安装Java虚拟机'); } } </script> </head> </html>使用VBScript检测方法为： view plaincopy to clipboardprint? <SCRIPT LANGUAGE="VBScript"> on error resume next If isIE = "true" Then If Not(IsObject(CreateObject("JavaWebStart.isInstalled"))) Then javawsInstalled = 0 Else javawsInstalled = 1 End If If Not(IsObject(CreateObject("JavaWebStart.isInstalled.1.4.2.0"))) Then javaws142Installed = 0 Else javaws142Installed = 1 End If If Not(IsObject(CreateObject("JavaWebStart.isInstalled.1.5.0.0"))) Then javaws150Installed = 0 Else javaws150Installed = 1 End If msgbox javawsInstalled End If </SCRIPT>