Need help with creating a looping mp3 or swf

I want to upload a audio file to play as background music on my website.  I use an online website builder, and the template creates a flash website.  I can upload an mp3 or swf file of less than .5mb. The web tech guys say I have to change a setting in the mp3 file so it automatically loops (the web template only plays it once without this setting).  I have searched the internet, downloaded audacity, acid express, soundforge trial, but I cannot figure it out.  I have also read several places that looping an mp3 file leaves a slight break each time it loops.  I did get the web tech guys to convert my mp3 into a swf (I don't have flash software), but it has an annoying pause each time it loops.

Any suggestions will be greatly appreciated.  thanks.