Выделение большого объема памяти

    ZeroMemory( &ofn , sizeof( ofn));
    ofn.lStructSize = sizeof ( ofn );
    ofn.hwndOwner = NULL  ;
    ofn.lpstrFile = szFile ;
    ofn.lpstrFile[0] = '\0';
    ofn.nMaxFile = sizeof( szFile );
    ofn.lpstrFilter = "All\0*.*\0Text\0*.TXT\0";
    ofn.nFilterIndex =1;
    ofn.lpstrFileTitle = NULL ;
    ofn.nMaxFileTitle = 0 ;
    ofn.lpstrInitialDir=NULL ;
    ofn.Flags = OFN_PATHMUSTEXIST|OFN_FILEMUSTEXIST

      .open:
 
        invoke  GetOpenFileName,ofn
        invoke  CreateFile,buffer,GENERIC_READ or GENERIC_WRITE,FILE_SHARE_READ or FILE_SHARE_WRITE,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_ARCHIVE,NULL
        mov     [hfile],eax
        invoke  GetFileSize,[hfile],NULL
        mov     [filesize],eax
        inc       eax
        mov     [memsize],eax
        invoke  GlobalAlloc,GMEM_ZEROINIT OR GMEM_MOVEABLE,[memsize]
        mov     [hmem],eax
        invoke  GlobalLock,[hmem]
        mov     [hmemory],eax
        invoke  ReadFile, [hfile],[hmemory],[filesize],kolwrbait,NULL
        invoke  CloseHandle, [hfile]
        invoke  GetSaveFileName,ofn1
        invoke  CreateFile,buffer1,GENERIC_READ or GENERIC_WRITE,FILE_SHARE_READ or FILE_SHARE_WRITE,NULL,OPEN_ALWAYS,FILE_ATTRIBUTE_ARCHIVE,NULL
        mov     [hfile],eax
        xor     eax,eax
        mov     [kolwrbait],eax
        invoke  WriteFile, [hfile],[hmemory],[filesize],kolwrbait,NULL
        invoke  CloseHandle, [hfile]
        invoke  GlobalUnlock,[hmem]
        invoke  GlobalFree,[hmem]
        jmp     .finish
 
 
  filesize  dd ?
  memsize   dd ?
  hmem      dd ?
  hmemory   dd ?
  kolwrbait dd ?
  buffer rb MAXSIZE
  buffer1 rb MAXSIZE
 
  filter_string db 'All Files',0,'*.*',0
                db 'Text Files',0,'*.txt',0,0
 
  hfile     dd ?
  edithwnd  dd ?
  editfont  dd ?
  memfreesize  dd 800000000
 
 
  wc WNDCLASS 0,WindowProc,0,0,NULL,NULL,NULL,COLOR_BTNFACE+1,NULL,_class
  msg MSG
  client RECT
 
  ofn OPENFILENAME sizeof.OPENFILENAME,0,0,filter_string,0,0,0,buffer,MAXSIZE,0,0,0,0,OFN_EXPLORER or OFN_FILEMUSTEXIST or OFN_PATHMUSTEXIST,0,0,0,0,0,0
  ofn1 OPENFILENAME sizeof.OPENFILENAME,0,0,filter_string,0,0,0,buffer1,MAXSIZE,0,0,0,0,OFN_EXPLORER or OFN_FILEMUSTEXIST or OFN_PATHMUSTEXIST,0,0,0,0,0,0