Ringtones on A840

Hi everyone,

I just bought a Motorola A840 with a 256Mb Transflash card. The salesperson told me that I could opy Mp3 files onto the card then use them as ringtones. I've tried several times to get it to work, but it just won't. Has anyone succeeded in adding tones to it? If so, how? The only thing I can do with the songs I've copied onto the card is play them as an mp3 player - not quite what I had in mind.

Thanks