Can I Use Java Script in eDesigner Forms ?

The creation of JavaScript requires expertise at doing so. It should really only be used for tasks that cannot be achieved through the standard product and even then we would urge caution, as without due diligence, you could inadvertently cause issues that are difficult to support.

You would need to create the JavaScript and place in Resources and regression test to assure no issues elsewhere. If you are unsure on how to create the JavaScript we don't recommend you do this task as it requires expertise in this area.