(N)ASM LoadLibrary,GetProcAddress and MessageBox!

When i was reading shellcode writing tutorial The LoadLibrary and GetProcAddress was been just confused me. But it was really easy to understand in normal asm code. It was bit harder for me when i first tried to write a bit dynamic windows shellcode.  So for understanding the dynamic dll loading in shellcode first i decide to learn to load the dll dynamically in normal (n)asm code and it was easy:

section .data

ldlibry dd  0
pro dd  0
dll db  "user32.dll",0
myFtion db  "MessageBoxA",0
MSG db  "ASM GetProcAddress",0

extern _LoadLibraryA@4
extern  _FreeLibrary@4
extern  _GetProcAddress@8
extern  _ExitProcess@4

global _start

section .text

_start:
    push    dll         ;push user32.dll
    call    _LoadLibraryA@4     ;Call the API.
    mov [ldlibry],eax       ;eax hold return address. So eax=LoadLibrary("user32.dll") and now ldlibry=LoadLibrary("user32.dll")
    
    ;now we need to call GetProcAddress
    
    push    myFtion         ;The API name we are going to call
    push    eax         ;LoadLibrary("user32.dll")
    call    _GetProcAddress@8   ;GetProcAddress(LoadLibrary("user32.dll"),"MessageBoxA"). Again eax holding the return address
    
    
    push    0x0         ;MB_OK
    push    MSG         ;TITLE="ASM GetProcAddress"
    push    MSG         ;Messgage="ASM GetProcAddress"
    push    0           ;Reserved=0
    call    eax         ;Call MessageBoxA through GetProcAddress. 
    
    push    dword [ldlibry]     ; ldlibry holding the LoadLibrary("user32.dll"). Again load to Free up.
    call    _FreeLibrary@4      ;Call the Windows api FreeLibrary()
    
    ;We should exit the process otherwise it may cause "access violation"
    push    0           ;load 0 to stack        
    call    _ExitProcess@4      ;Call ExitProcess
    
    
    ;Assembl:
    ;nasm -fwin32 ldlibrary.asm
    ;ld -o ldlibrary.exe ldlibrary.obj -lkernel32