Steve,

Yesterday evening, I tested all the possibilities again after I made a new program which is only one loop. It was checking the button first after it was passing to SERIN2 command and passing to control what was arrived by SERIN2. Anyhow I have to tell you that the serin or serin2 command does not work with any button control. I tested all the timeout figures starting from 2 ms up to 2000 ms. I am sure there is a bug in the compiler.
I tested again the HSERIN command by making some changing on the pcb and I saw that it is working very well. Today I will change all the PCB and the program for working with HSERIN command.

I wanted to give you again the result of my work which can be intersting for other people.
Thanks again for your helps.

Regards
Ero