Thanks chaps you helped me back on the right path...you were right 4li4s but I still very carefully followed http://documentation.mamp.info/en/mamp/installation/updating-mamp - as I already have a version of MAMP in the Applications folder.
Big boo-boo I made: Trying to be clever I moved the MAMP folder out of Applications thinking I would have a back-up - bad move I lost all my websites! - hello 'Time Machine' you saved the day! Talk about going round-the-mulberry bush, good grief!
Thanks for your quick assistance, I'll be back to try and help others if I can!
Cheers!