Live_search observe_form - manual call

I am using the observe_form to create a live search. The user types in
the specified search phrase and the div below is populated with the
matches. The user can click on a match below and go to a new page that
shows information about that match. I am trying to create a “back”
button that allows the user to return to the previous search so that the
list is still showing.

So far, I am passing the search phrase back to to the search page and
filling the text box, but how do I fire off the live search without
changing what is in the text box?