GetProcAddress and Loadlibrary

Hi everybody,

Today I'm trying to code a very simple application that simply demonstrated how to use keyboard hook and started to use LoadLibrary and GetProcAddress API function. However, when I make a call to GetProcAddress, the 1st function was retrieved sucessfully but not the second. After examing the symbol name in the dll file, I'v found them to be still correct. So where the thing goes wrong ?
I include here the source code of both DLL file and main application. You can compile it right away and see it yourself.

DLL CODE

Code:

format PE GUI 4.0 DLL
entry DllMain

include "win32a.inc"
include "\macro\if.inc"



section '.data' data readable writeable shareable
     msg1 db "Ko bam phim xuong",0
     msg2 db "Call nexthook",0
 hook dw 0

section '.code' code readable executable
proc DllMain hinstDLL,fdwReason,lpvReserved
  mov eax,TRUE
        ret
endp


proc KBHookSetup DLL_module

      mov eax,[DLL_module]
        invoke SetWindowsHookEx,WH_KEYBOARD,KBHookFilter,dword [eax],0
      mov dword [hook],eax
ret
endp

proc KBHookFilter keycode,wParam,lParam
     mov ebx,[lParam]
    shr ebx,31
  mov eax,[keycode]
      .if eax = HC_ACTION
         .if ebx = 0
                 .if [wParam]=30h
                            invoke MessageBox,NULL,msg1,NULL,MB_OK
                      .endif
              .endif  
    .else
               invoke MessageBox,NULL,msg2,MB_OK
           mov eax,[keycode]
              mov ebx,[wParam]
            mov ecx,[lParam]
    
            invoke CallNextHookEx,dword [hook],eax,ebx,ecx
              ret
 .endif
xor eax,eax   
ret
endp



section '.edata' export data readable 
  export 'HOOKDLL.DLL',\
  KBHookSetup,'KBHookSetup',\
  KBHookFilter,'KBHook'
     

section ".idata" import data readable writeable
   library kernel32,'kernel32.dll',\
                user32,'user32.dll'
       import user32,\
             MessageBox,'MessageBoxA',\
               SetWindowsHookEx,'SetWindowsHookExA',\
           CallNextHookEx, 'CallNextHookEx'

section '.reloc' fixups data discardable

Main Application code

Code:

include 'win32ax.inc'
include 'rc.inc'

.data

msg MSG
nResult dw 0
hModule dw 0
hook dw 0 
Dll_module dw 0
_dll_hook_setup dw 0
_dll_hook_filter dw 0
error db 1,2,3,4
    db      "can't load the module",0
 kbh db "KBHookSetup",0
 kbf db "KBHookFilter",0        
 .code       
start:
  
    invoke  GetModuleHandle,NULL
        mov dword [hModule],eax
     invoke  DialogBoxParam,eax,IDD_DLG1001,NULL,DLG_Function,NULL
       .if eax = 0
         mov dword [nResult],eax
             invoke MessageBox,NULL,"Hi! I'm the example program!","Win32 Assembly",MB_OK
   .endif
      
    invoke UnhookWindowsHook,[hook]
     invoke  ExitProcess,0

proc DLG_Function,hwnd,uMsg,wParam,lParam

mov eax,[uMsg]
cmp eax ,WM_DESTROY
jz .wm_destroy
cmp eax,WM_COMMAND
jz .wm_command
cmp eax,WM_CLOSE
jz .wm_close
cmp eax,WM_INITDIALOG
jz .wm_initdialog
jmp .default

.wm_initdialog:
      invoke LoadLibrary,"C:\HOOKDLL.DLL"
      mov dword [Dll_module],eax
  .if eax =  0
                        invoke MessageBox,NULL,"the specified modulesss could not be found",NULL,MB_OK
                    invoke ExitProcess,0
        .endif
      mov ecx,dword [Dll_module]
  invoke GetProcAddress,ecx,"KBHookSetup"
   mov dword [_dll_hook_setup],eax
     .if eax=0
           invoke MessageBox,NULL,"Can't get the function address setup",NULL,MB_OK
         invoke FreeLibrary,[Dll_module]
             invoke ExitProcess,NULL
     .endif
      mov ecx,dword [Dll_module]
  invoke GetProcAddress,ecx,"KBHook"
        mov dword [_dll_hook_filter],eax
    .if eax = 0
         invoke MessageBox,NULL,"Can't get the function address filter",NULL,MB_OK
                invoke FreeLibrary,[Dll_module]
             invoke ExitProcess,NULL
     .endif
      
    invoke _dll_hook_setup,Dll_module

       mov dword [hook],eax
        jmp .exit
.wm_destroy:
   invoke PostQuitMessage,,NULL
        jmp .exit
.wm_command:
   mov eax, [wParam]
   .if ax = IDC_BUTTON_EXIT
            shr eax,16
          .if ax=BN_CLICKED                     ;click exit buttion
                   mov eax,[hwnd]
                      invoke DestroyWindow,[hwnd]
                 invoke FreeLibrary,[Dll_module]
             .endif
      .endif
      jmp .exit
.wm_close:
     mov eax,[hwnd]
      invoke EndDialog,eax,nResult
        jmp .exit
.default:
      mov eax,FALSE
       ret
.exit:
       mov eax,TRUE

ret
endp



.end start

section '.rsrc' data readable resource from 'rc.res'