Sorry to seem picky. It's an area which, because it's not well defined for C, can lead to difficult problems, especially in porting between different manufacturers compilers & code written by different groups of people at different times.

I still work a lot in assembler, where I tend to use the C approach of zero & not zero, rather than FALSE & TRUE.

Re. auto-quote :
On clicking the save button I get a message saying that the option is part of
Premier Unviversal Thread Membership.

Thanks
Paul