how can i add an item to the listbox (newbie)

its just one or two days i have downloaded fams and i try to learn somethings from the examples
just have a look at my source code and tell me about the wrong things i have done and how to solve the listbox problem that i got please...

format PE GUI 4.0
entry start

include '%include%\win32a.inc'

IDC_Button1 = 1
IDC_Static1 = 2
IDC_Static2 = 3
IDC_Edit1 = 4
IDC_Button2 = 5
IDC_Button3 = 6
IDC_Listbox1 = 7

section '.data' data readable writeable

flags dd ?
;LB_ADDSTRING = &H180
caption rb 40h
message rb 100h
infotext1 db 'Bu program FASM v1.48 (Flat Assembler)',0dh,0ah,\
'Kullanılarak VeSCeRa-YSG Tarafından',0dh,0ah,\
'Deneme AmaÃ§lı Olarak Yazılmıştır',0
infotext2 db 'Program Hakkında',0

section '.code' code readable executable

start:

invoke GetModuleHandle,0
invoke DialogBoxParam,eax,37,HWND_DESKTOP,DialogProc,0
or eax,eax
jz exit
exit:
invoke ExitProcess,0

proc DialogProc,hwnddlg,msg,wparam,lparam
enter
push ebx esi edi
cmp [msg],WM_INITDIALOG
je wminitdialog
cmp [msg],WM_COMMAND
je wmcommand
cmp [msg],WM_CLOSE
je wmclose
xor eax,eax
jmp finish

wminitdialog:

jmp processed

wmcommand:
cmp [wparam],BN_CLICKED shl 16 + IDC_Button1
je wmclose
cmp [wparam],BN_CLICKED shl 16 + IDC_Button2
je addtolist
cmp [wparam],BN_CLICKED shl 16 + IDC_Button3
je showinfo
jmp processed

showinfo:
invoke MessageBox,[hwnddlg],infotext1,infotext2,MB_OK
jmp processed

addtolist:
invoke SendMessage,[hwnddlg],LB_ADDSTRING,'test',IDC_Listbox1
; i know that this is wrong but i guess it is something like this
; can you show me a source to have all these stuff written and tells how to use the calls
; i am first trying to add 'test' than i will try to add the
;string from IDC_Edit1 if you can help about that it will be great too
jmp processed

wmclose:
invoke EndDialog,[hwnddlg],0

processed:
mov eax,1

finish:
pop edi esi ebx
return

section '.idata' import data readable writeable

library kernel,'KERNEL32.DLL',\
user,'USER32.DLL'

import kernel,\
GetModuleHandle,'GetModuleHandleA',\
ExitProcess,'ExitProcess'

import user,\
DialogBoxParam,'DialogBoxParamA',\
MessageBox,'MessageBoxA',\
SendMessage,'SendMessageA',\
EndDialog,'EndDialog'

section '.rsrc' resource data readable

directory RT_DIALOG,dialogs

resource dialogs,\
37,LANG_TURKISH+SUBLANG_DEFAULT,demonstration

dialog demonstration,'Assembly ile Win32',100,100,185,175,WS_CAPTION+WS_POPUP+WS_SYSMENU
dialogitem 'BUTTON','Kapat',IDC_Button1,130,156,45,15,WS_VISIBLE+WS_TABSTOP+BS_PUSHBUTTON
dialogitem 'BUTTON','Bilgi',IDC_Button3,80,156,45,15,WS_VISIBLE+WS_TABSTOP+BS_PUSHBUTTON
dialogitem 'STATIC','Bu program Flat Assembler v1.48 kullanılarak',IDC_Static1,10,10,200,8,WS_VISIBLE
dialogitem 'STATIC','VeSCeRa-YSG tarafından yazılmıştır.',IDC_Static2,10,18,200,8,WS_VISIBLE
dialogitem 'LISTBOX',NULL,IDC_Listbox1, 10, 30, 165, 60, WS_VISIBLE+WS_BORDER
dialogitem 'EDIT','',IDC_Edit1,10,80,165,13,WS_VISIBLE+WS_BORDER+WS_TABSTOP
dialogitem 'BUTTON','Ekle',IDC_Button2,130,95,45,15,WS_VISIBLE+WS_TABSTOP+BS_PUSHBUTTON
enddialog