I'm using autocomplete and referencing a local array.  eg.

var foo = new Array("apple","ape");
$("#myinput").autocomplete(foo);

What I'd like to do:
When the user hits a button, if the value in #myinput isn't part of foo, add it. 
Then clear the value and the user starts over.
but this time, (this is what I don't know how to do), have the autocomplete use the new foo.

Is there a way to refresh the 'reference' to the local array that autocomplete uses? or add to it?

Many thanks.  This plugin rocks.