Music on hold

Hi,
I install Asterisk now 1.5 with Freepbx 2.5.1.5
I try upload mp3 file to music on hold.
I choose file and click upload, after some second my web page say:

"The connection was reset

The connection to the server was reset while the page was loading

*   The site could be temporarily unavailable or too busy. Try again in a few
      moments.

*   If you are unable to load any pages, check your computer's network
      connection.

*   If your computer or network is protected by a firewall or proxy, make sure
      that Firefox is permitted to access the Web.

File not uploading.

Please help me.

I try now upload small wav file and i get:

Error Processing: “sox: Can’t open input file ‘/var/lib/asterisk/mohmp3/orig_mail.wav’: No such file or directory” for mail.wav!

Music on hold not working.