It's pretty easy, just follow the few simple steps below:
1. Create an environment
Go to Jelastic.com and sign up if you haven't done it yet or log in with your Jelastic credentials by clicking the Sign In link on the page.
While in Jelastic dashboard, click the Create environment button:
In the Environment topology window select Tomcat 6 as your application server, type your environment name, for example, orbeon, and click Create.
It will take just a minute for your environment to be created.
2. Upload a Java package
Go to the Orbeon web site and download the latest Orbeon Forms community edition.
Extract the files from the zip package you have just downloaded and upload the orbeon.war file to the Deployment manager.
Once the package is in Jelastic, deploy it to the environment you have just created.
Now you can open Orbeon Forms in a web browser and use all its functions!