ok, I downloaded the latest java (jre7). Now I can see the simulation on a web page. But, now I have another problem.
When I try to run the same simulation within EJS console, it produces a compilation error as follows:

[b]Compilation produced an error!
Generating simulation file Pend……
C:\Users\Umar\Documents\A_Sithy\SithyJava\EJS_4.1\workspace\output\users\Sithy\Pendulum.java:19: cannot access java.lang.Object
bad class file: C:\Program Files\Java\jre7\lib\rt.jar(java/lang/Object.class)
class file has wrong version 51.0, should be 49.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
public class Pendulum extends org.colos.ejs.library.AbstractModel {
      ^  [/b]

It is caused by the new installation. How do I go about fixing this. Any help would be appreciated. I have several simulation files. I want to edit them and run them within the EJS console and eventually package it to display on a website.

Thank you for your expertise.