Senka11,
Во-первых код заключать нужно в тег [code] (#)... или использовать
утилиту для раскраски
Код:

#include <GUIConstants.au3>
GUICreate("Computer ID system created by Senka!", 320, 200)
GUICtrlCreateLabel("Input Computer ID", 10, 10)
$OK_Button = GUICtrlCreateButton("Ready", 110, 120, 60)
$nEdit = GUICtrlCreateInput("inventory no.", -1, 3, 175, 20)
$aEdit = GUICtrlCreateInput("Everest no.", -1, 30, 175, 20)
GUISetState()
While 1
$nMsg = GUIGetMsg()
Switch $nMsg
Case $GUI_EVENT_CLOSE
MsgBox(0, "GUI Event", "You clicked CLOSE! Exiting...")
Exit
Case $OK_Button
MsgBox(0, "11", "You pressed OK!")
Local $sDataFrom_nEdit = GUICtrlRead($nEdit)
Local $sDataFrom_aEdit = GUICtrlRead($aEdit)
Local $hOpenFile = FileOpen("Data.txt", 1)
FileWriteLine($hOpenFile, _
"Data from $nEdit: " & $sDataFrom_nEdit & @CRLF & _
"Data from $aEdit: "& $sDataFrom_aEdit)
FileClose($hOpenFile)
EndSwitch
WEnd