That doesn't work.
 
All Expressions like
| #{javascript:viewScope.EAN} | 
are failing in the clientside script block. 
The evaluator of the editor doesn't allow to save this, because there is a 'content  with runtime binding'.
 
Are there any other proposals ?
Idea: i write the whole script block serverside as pure HTML Code in a text field. Then i can embed the value. 
 
@Dan:
i don't know to integrate XSP.getElementById("#{id:inputHidden1}").value into my csjs ???
Nevertheless I think that would be the same problem as described above.