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It always happens in my Win32 Programs....right after a Show a Window, and I want to jump to something, as soon as I jump , the window dissappears and the program closes....try it and you'll see....like for instance

anything:
; Code
return

if you jmp anything after you show the window the window closes, automatically....why is that?

Ok here it is, all the code

format PE GUI 4.0                                                                                              

entry start                                                                                                    

                                                                                                               

include 'include\kernel.inc'                                                                                   

include 'include\user.inc'                                                                                     

                                                                                                               

include 'include\macro\stdcall.inc'                                                                            

include 'include\macro\import.inc'                                                                             

                                                                                                               

section '.data' data readable writeable                                                                        

                                                                                                               

  mainhwnd dd 0                         ; handle of window                                                     

  hinstance dd 0                        ; handle of module                                                     

                                                                                                               

  msg MSG                                                                                                      

  wc WNDCLASS                                                                                                  

                                                                                                               

  _title db 'My Window',0                                                                                      

  _class db 'FASMWIN32',0                                                                                      

                                                                                                               

section '.code' code readable executable                                                                       

                                                                                                               

  start:                                                                                                       

                                                                                                               

        invoke  GetModuleHandle,0                                                                              

        mov     [hinstance],eax                                                                                

        invoke  LoadIcon,0,IDI_APPLICATION                                                                     

        mov     [wc.hIcon],eax                                                                                 

        invoke  LoadCursor,0,IDC_ARROW                                                                         

        mov     [wc.hCursor],eax                                                                               

        mov     [wc.style],0                                                                                   

        mov     [wc.lpfnWndProc],WindowProc                                                                    

        mov     [wc.cbClsExtra],0                                                                              

        mov     [wc.cbWndExtra],0                                                                              

        mov     eax,[hinstance]                                                                                

        mov     [wc.hInstance],eax                                                                             

        mov     [wc.hbrBackground],COLOR_BTNFACE+1                                                             

        mov     [wc.lpszMenuName],0                                                                            

        mov     [wc.lpszClassName],_class                                                                      

        invoke  RegisterClass,wc                                                                               

                                                                                                               

        invoke  CreateWindowEx,0,_class,_title,WS_VISIBLE+WS_MINIMIZEBOX+WS_MAXIMIZEBOX+WS_SYSMENU+WS_THICKFRAM

        mov     [mainhwnd],eax                                                                                 

        jmp     anything                                                                                       

                                                                                                               

  msg_loop:                                                                                                    

        invoke  GetMessage,msg,NULL,0,0                                                                        

        or      eax,eax                                                                                        

        jz      end_loop                                                                                       

        invoke  TranslateMessage,msg                                                                           

        invoke  DispatchMessage,msg                                                                            

        jmp     msg_loop                                                                                       

                                                                                                               

  end_loop:                                                                                                    

        invoke  ExitProcess,[msg.wParam]                                                                       

  anything:                                                                                                    

  ;doesn't matter what it is                                                                                   

  return                                                                                                       

                                                                                                               

proc WindowProc, hwnd,wmsg,wparam,lparam                                                                       

        enter                                                                                                  

        push    ebx esi edi                                                                                    

        cmp     [wmsg],WM_DESTROY                                                                              

        je      wmdestroy                                                                                      

  defwndproc:                                                                                                  

        invoke  DefWindowProc,[hwnd],[wmsg],[wparam],[lparam]                                                  

        jmp     finish                                                                                         

  wmdestroy:                                                                                                   

        invoke  PostQuitMessage,0                                                                              

        xor     eax,eax                                                                                        

  finish:                                                                                                      

        pop     edi esi ebx                                                                                    

        return                                                                                                 

                                                                                                               

section '.idata' import data readable writeable                                                                

                                                                                                               

  library kernel,'KERNEL32.DLL',\                                                                              

          user,'USER32.DLL'                                                                                    

                                                                                                               

  kernel:                                                                                                      

  import GetModuleHandle,'GetModuleHandleA',\                                                                  

         ExitProcess,'ExitProcess'                                                                             

                                                                                                               

  user:                                                                                                        

  import RegisterClass,'RegisterClassA',\                                                                      

         CreateWindowEx,'CreateWindowExA',\                                                                    

         DefWindowProc,'DefWindowProcA',\                                                                      

         GetMessage,'GetMessageA',\                                                                            

         TranslateMessage,'TranslateMessage',\                                                                 

         DispatchMessage,'DispatchMessageA',\                                                                  

         LoadCursor,'LoadCursorA',\                                                                            

         LoadIcon,'LoadIconA',\                                                                                

         UpdateWindow,'UpdateWindow',\                                                                         

         SetParent,'SetParent',\                                                                               

         PostQuitMessage,'PostQuitMessage'                                                                     

                                                                                                               

Thanks Privalov!

If you want to call you procedure conditionally you can do it so:

  cmp [something], value

  jne .skip_call

  call some_proc

.skip_call:

jnl, jnle, jnge and so on :) - use your brain to generate the answer ;)

Right.