Dear Steve,
Thank you for the tricks. You right I checked the program again and I saw that there are a lot of cunfusions. It was working but as you have said the reason can be the stack due to that cınfusions.Anyhow, I changed the program to make one loop only. I taken out all the zig-zags in the program. I did not yet tried. I was busy. I will try it within two days and let you know the result.

It would be good idea if I can check the program with one debugger. It is a pity that I have not mcs plus. By the way I would see where the program was going without touching the button command.

Thanks again
ERO