Synchronise Input Controls via WM_COMMAND

#include <WindowsConstants.au3>
#include <GUIConstants.au3>
#include <EditConstants.au3>
#include <Winapi.au3>

$hGUI = GUICreate("Test", 200, 100)
$cInput1 = GUICtrlCreateInput("", 5, 5, 190, 25)
$cInput2 = GUICtrlCreateInput("", 5, 35, 190, 25)
GUISetState()

GUIRegisterMsg($WM_COMMAND, "_WM_COMMAND")

While True
    Switch GUIGetMsg()
        Case $GUI_EVENT_CLOSE
            Exit
    EndSwitch
WEnd

Func _WM_COMMAND($hWnd, $iMsg, $wParam, $lParam)
    If $WM_COMMAND = $iMsg Then
        Switch $hWnd
            Case $hGUI
                Switch BitAND($wParam, 0xFFFF)
                    Case $cInput1
                        Switch BitShift($wParam, 16)
                            Case $EN_CHANGE
                                GUICtrlSetData($cInput2, GUICtrlRead($cInput1))
                        EndSwitch
                EndSwitch
        EndSwitch
    EndIf
EndFunc   ;==>_WM_COMMAND