Why I do not get integrated HTML or JS Reference?

Hello,

I started with an empty Web-Module and wanted to develep some html / js. ( native js, no further libs at this point )

Code completion works as suspected but I wonder why I don't get any HTML or JS reference?

For instance if I am on a div - tag or on a Date - Object and Press ctrl + J the popUp allways tells me "No Documentation avaiblable".

Javascript support Plugin is activated.

html has .html - Extension and js has .js -Extension.

Its IntelliJ 11.1.4 on MacOS.

Thanks for looking.

Ingo

Btw: Within CSS there I get a Reference using ctrl + J.