How to implement this kind of autocomplete?

The field is used for tag name input,and multiple tag names can be
inputed.
The traditional textfield_autocomplete will not work after select the
one from the pop menu,how to continue with the autocomplete if i want to
go on with the field inputing?

perhaps the tokens option of auto_complete_field can satisfy this
requirement?
:tokens: A string or an array of strings containing separator tokens for
tokenized incremental autocompletion. Example: :tokens => â??,â?? would
allow multiple autocompletion entries, separated by commas.

however if i use tokens => ‘,’ for example,
after i get the tag name “123” displayed in the textfield,and continue
with a input of comma,then the pop menu display again,but nothing will
happen if I selected one of the popmenu items.

Anybody who has met such a kind of situation?

Very grateful!

Charlie wrote:

The field is used for tag name input,and multiple tag names can be
inputed.
The traditional textfield_autocomplete will not work after select the
one from the pop menu,how to continue with the autocomplete if i want to
go on with the field inputing?