I have a confession to make. I use global variables all the time. I know, everybody says that its bad form, not proper OO programming, makes for difficult code maintenance, sets me up for disastrous problems and lots of other things too. But, I find them handy and easy to work with. I also know that all of the code that I write is ANSI C for embedded processors that no one else is ever going to look at, much less maintain. Most of the software is simple and straightforward, and global variables are very easy to work with. I realize that globals can be modified by any routine in the code, but that's the whole point of using them.
So, given the circumstances, what's wrong with them?