"You're probably missing plugin.jar in your classpath/build path. It's in the same 'lib' directory as rt.jar." ( found at: http://www.javaworld.com/...mp;page=51 )
For JRE6 bundled with JDK 6u18 the path for this jar is: C:\<ProgramFiles>\Java\jdk1.6.0_18\jre\lib\plugin.jar
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For JRE6 bundled with JDK 6u18 the path for this jar is: C:\<ProgramFiles>\Java\jdk1.6.0_18\jre\lib\plugin.jar