[Typo3] Conditions by using user functioons

[tapio]

tapio wrote:

> I would need for BE-editing corresponding conditions
> to define an additional LINK element for CSS in order to control better 
> BE users/ BE user groups in BE-editing.
> 
> The BE uses now stylesheet_post.css but I would like to add an extra CSS 
> file.

http://typo3.org/documentation/document-library/doc_core_api/TBE_STYLES/

gives some instructions and I tried this

	$TBE_STYLES['stylesheet2']='/fileadmin/template/main/css/fe-buttons.css';

but that didn't create any LINK element, which has that CSS-file for 
BE-editing.