How To Do Autocomplete With Every Word In A Text Field?

Dear fellows,

my question is concerning autocompletion in a text field. What I want to achieve, is an autocompletion, that is triggerd via hashtags (#) or @-signs and happens in all of the textfield, also repeatedly, just like Facebook does. I experimented with CJuiAutoComplete, but it only seems to autocomplete once, and does not react to further text being entered. Is there a hidden option I should know, or is this widget just not the right way to do this?

There are a lot of jquery plugins for that (five seconds in google gave me this and this)

Thank you.