Eclipse PDT - Javascript Code Assist is not work?

I have try PDT 2.1开发者_高级运维.2 and 2.2 nighty build , both of them , javascript code assist is not work when editing php file. I have check the JSDT,WTP Plugin is loaded and no error. But when i open a *.js file, it works , is it any configuration i miss?

... Why would the javascript code assist help you when editing a php file? A javascript helper has no business in a PHP file.