jsp检测是不是安装jre

关于Applet在客户端运行时，如果没有jre会下载安装jre的问题，以下的这段代码能够实现如果没有jre1.5.0_09

则会下载安装：

<object classid = "clsid:CAFEEFAC-0015-0000-0009-ABCDEFFEDCBA"
codebase = "http://java.sun.com/update/1.5.0/jinstall-1_5_0_09-windows-i586.cab#Version=5,0,90,3"
WIDTH = "500" HEIGHT = "400" >
<PARAM NAME = CODE VALUE = "HelloWorld" >
<param name = "type" value = "application/x-java-applet;jpi-version=1.5.0_09">
<param name = "scriptable" value = "false">
<comment>
<embed type = "application/x-java-applet;jpi-version=1.5.0_09"
CODE = "HelloWorld"
WIDTH = "500" HEIGHT = "400"
scriptable = false
pluginspage ="http://java.sun.com/products/plugin/index.html#download">
<noembed> </noembed>
</embed>
</comment>
</object>