rich:editor ltr and rtl buttons

[asafz]

Hi,
I'm using rich:editor in my project.
I'm trying to add ltr and rtl buttons to the editor by using the following syntax:
<f:param name="theme_advanced_buttons1" value="ltr,rtl,outdent,indent,|,link,unlink" />
<f:param name="theme_advanced_buttons2" value=""/> <f:param name="theme_advanced_buttons3" value=""/>
<f:param name="theme_advanced_toolbar_location" value="top" />

unfortunatlly the editor is not displaying the ltr and rtl buttons.

is rich:editor supports these buttons?
am I missing something here?

thanks.

[ilya_shaikovsky]

probably you forgot to add directionality plugin.

[asafz]

what is the syntax for adding this plugin?

should I add a file to the class path or something like that?