Differences between relative_url using Rails with Prototype or JQuery

My web app is deployed with Passenger in a sub-uri,
http://www.mydomain.com/vacademy/
and I am displaying a player in a page
the swf is located in …/public/dist/flowplayer-3.1.5.swf

Using Prototype library I wrote a script :

$f("player", "./dist/flowplayer-3.1.5.swf", { .... and I don't have any problem to get the player installed from http://www.mydomain.com/vacademy/dist/flowplayer-3.1.5.swf but when using jQuery $(function() { ...... $f("player2", "./dist/flowplayer-3.1.5.swf", { ... the .swf is not found as the relative url is based on the controller ... http://www.mydomain.com/vacademy/mycontroller/dist/flowplayer-3.1.5.swf is there anyway to bypass this behavior, not using a relative path or getting the rails public path in js ? thanks for your help erwin