Hi everyone, i have a problem which I hope someone can help me with!

when my stereo is on, every few mins the sound mutes and phone appears on screen and after a few second it usually comes back on. Its getting rather annoying and to make matters worse I stupidly lost my audio manual (dips##t!!!) so im not sure what model it is and what my radio code is but it is the standard item in the 2008 focus zetec 1.8

I paid a visit to my local ford dealer and was quoted 91 just to look into the problem so any help will be really appreciated

thanks for reading!!!