How To Create Window with CreateWindowEx ?

I fail badly when i try to create a window with this api-call.

here is the code: (i am sure there are lot of bugs or so, but the compiler does not complain)

Global CreateWindowEx(window,Title$z,message$z, flags,x,y,w,h,Parent,guiid, hInstance,dunno);

Const WS_OVERLAPPED	= 0
Const WS_VISIBLE	= $10000000

user32 = LoadLibraryA ("user32.dll")
If user32=Null
	Notify("Konnte user32.dll nicht laden.")
Else
	CreateWindowEx=GetProcAddress(user32,"CreateWindowExA")
EndIf

CreateWindowEx(0,"jofgddfggdf","dgfdgf",WS_OVERLAPPED | WS_VISIBLE,0,0,640,480,0,0,hInstance,Null)


While Not KeyDown(KEY_ESCAPE)
Wend