Koraks - Apologies for not putting the code into a grey box, how do I do that? Thanks so much for your very detailed reply, although unfortunately a lot of it has gone over my head.
I have removed the stray ';' and added 'int' as pointed out by 'runaway_pancake' and it now compiles so I now have something to work with. I will now persevere with your information to sort out the 4 variables, so thanks again for your time. Although I might be back again if I can't sort them out!!
'runaway_pancake' - Thanks for pointing out my 2 mistakes, I should have noticed the stray ';' but would not have found the missing 'int' without your help, It now compiles OK with no messages, so again thanks for your help.