Problem with the cached wav file in embed tag

Hi All,

In my webpage, I used the embed tag to refer to a wav file in the web
server. This wav file can be uploaded by the user. I found out that after
the new file has been updated correctly to the server, and after the browser
reload the page, but the browser still play the old file (most likely the
cached copy). Since the webpage is in a frame, I need to refresh the page in
the frame, then the new file is correctly played.

Can anybody tell me how to solve the problem (any means e.g. Javascript,
or I'm using PHP in the server side), so that the client doesn't need to
refresh the page manually to have the new sound file playing.

Rgds,
K.Lam