section '.data' data readable writeable 
first db 0
handle_to_output_stream dd 0 
reserved                                dd 0 
symbols_was_written     dd 0


proc increment, number
        mov [number], 99
        ret
endp


section '.code' code readable executable 
start: 
        stdcall increment, first
        xor ebx, ebx
        mov bl, [first]    

proc WindowProc uses ebx esi edi, hwnd,wmsg,wparam,lparam
        cmp     [wmsg],WM_DESTROY
        je      .wmdestroy
  .defwndproc:
        invoke  DefWindowProc,[hwnd],[wmsg],[wparam],[lparam]
        jmp     .finish
  .wmdestroy:
        invoke  PostQuitMessage,0
        xor     eax,eax
  .finish:
        ret
endp    

Helga: You have the "increment" procedure inside the ".data" section which is not marked as executable. So that increment code can't be executed.

section '.code' code executable
proc increment number
        mov [number], 99
        ret
endp    

I don't use proc macros and am typing from a keyboardless-tablet, but if you're looking for ideas, the fasm download examples folder has both 32 and 64 bit template.asm examples which contain procs. Not the best example maybe since they are WindowProcs called indirectly, but they look like:

Code:

proc WindowProc uses ebx esi edi, hwnd,wmsg,wparam,lparam
        cmp     [wmsg],WM_DESTROY
        je      .wmdestroy
  .defwndproc:
        invoke  DefWindowProc,[hwnd],[wmsg],[wparam],[lparam]
        jmp     .finish
  .wmdestroy:
        invoke  PostQuitMessage,0
        xor     eax,eax
  .finish:
        ret
endp    

There's no comma after the proc name, not sure if it matters. Definitely a good idea to understand these more before using, but the Examples folder may be able to unblock you if you're stuck today.

Thanks but is does not help me anyway. I moved it into such section

Code:

section '.code' code executable
proc increment number
        mov [number], 99
        ret
endp    

but it anyway does not change the value of the passed variable after processing. In the debugger i can see that it was executed but after checking variable which was passed as an procedure's argument i do not see any changes.

        mov     edx,[number]
        mov     byte [edx],99    

Helga wrote:

Thanks but is does not help me anyway. I moved it into such section

Code:

section '.code' code executable
proc increment number
        mov [number], 99
        ret
endp    

but it anyway does not change the value of the passed variable after processing. In the debugger i can see that it was executed but after checking variable which was passed as an procedure's argument i do not see any changes.

When you modify [number] you modify the value of parameter that was passed to procedure (and stored on the stack). If you passed an address of a variable in this parameter, you need to use this value as a pointer in order to modify that memory location:

Code:

        mov     edx,[number]
        mov     byte [edx],99    

mov edx, [number]    

 mov     byte [edx],99    

If you post a complete minimal example that we can assemble we could help you better.

format  PE Console  
entry   start                    

include 'C:\FASM\INCLUDE\win32a.inc'
include 'C:\FASM\INCLUDE\MACRO\PROC32.INC'
 
section '.data' data readable writeable 
first db 0

section '.code' code executable
proc increment number
        mov edx,[number] 
        mov byte [edx],99
        ret
endp

section '.code' code readable executable 
start: 
        stdcall increment, first
        xor ebx, ebx
        mov bl, [first]
        
FINISH :         

        invoke  ExitProcess, 0 
         
section '.idata' import readable 
        library kernel, 'KERNEL32.DLL',\ 
        ascidc,         'ascidc.dll',\
        user32,'USER32.DLL'
import  kernel,\         
        ExitProcess,    'ExitProcess'     

format  PE Console
entry   start

include 'win32a.inc'

section '.data' data readable writeable
first db 0

section '.code' code executable

proc increment number
        mov edx,[number]
        mov byte [edx],99
        ret
endp

start:
        stdcall increment, first
        xor ebx, ebx
        mov bl, [first]
        invoke  ExitProcess, 0

section '.idata' import readable

        library kernel, 'KERNEL32.DLL',\
        ascidc,         'ascidc.dll',\
        user32,'USER32.DLL'
        import  kernel,\
        ExitProcess,    'ExitProcess'    

Not really problems, but you don't need the second include of proc32 because win32a already includes it. Also you have two code sections, and although they have different flags I don't see any reason why they can't all be combined into one section. Plus the FINISH label is not used anywhere.