Changing Java version automatically

We have some packages that can run only if a specific Java version is installed, enabled and the others are disabled in the system. So, we want a small application that will enable only a specific Java version and disable all the others. This task can be done manually by Control Panel-Java Control Panel. Then click on Java Tab. Under Java Runtime Environment Settings, click "View...". This lists all the versions of Java installed in the system. For example, 1.6.0_22, 1.6.0_13, 1.6.0_7, etc. We want your application to enable a specific version; for example 1.6.0_7 only. This application should work for Windows XP, Vista, 7 and other windows operating systems. We prefer application developed in Java so that we can have it run in Windows, Mac and Linux systems. Is this something doable? Good luck. ## Deliverables In your bid, please specify the language you will use and the platforms that your application will be able to work.