Help ! "FORRTL: SEVERE (157): PROGRAM EXCEPTION - ACCESS VIOLATION" ERROR

Hi,

I am getting this error "forrtl: severe (157): Program Exception - access violation" in my Fortran codes. If you build and run the code, you can see that I have positioned the line of the problem with the use of "call system('pause')" in line 767. Then, if you push any button, the program gives "the error". Any ideas based on the declarations and code posted in the attached file? Thanks.

Emre