(AutoIT) Creating licence key input box

Serial_input.au3

#include <GUIConstantsEx.au3>

HotKeySet("{BACKSPACE}","_BackSpace")
Global $gui = GUICreate("...",600)
Global $Input = GUICtrlCreateInput("", 8, 150, 584, 35)
	GUICtrlSetLimit($Input,29)
	GUICtrlSetFont($Input,20)
Global $LastInput = ""
GUISetState()
Local $Temp, $LenPart = 5
While 1
	If $LastInput <> GUICtrlRead($Input) Then
		$LastInput = GUICtrlRead($Input)
		If StringLen($LastInput) = $LenPart Then
			$LastInput &= "-"
		Else
			$Temp = StringSplit($LastInput,"-")
			If $Temp[$Temp[0]] <> "" And StringLen($Temp[$Temp[0]]) >= $LenPart And StringLen(GUICtrlRead($Input)) < 29 Then
				$LastInput &= "-"
			EndIf
		EndIf
		GUICtrlSetData($Input,$LastInput)
	EndIf
	$Msg = GUIGetMsg()
	Switch $Msg
		Case $GUI_EVENT_CLOSE
			Exit

	EndSwitch
WEnd

Func _BackSpace()
	If Not WinActive($gui) Then Return 0
	If StringRight($LastInput,1) = "-" Then
		Return GUICtrlSetData($Input,StringLeft($LastInput,StringLen($LastInput)-2))
	Else
		Return GUICtrlSetData($Input,StringLeft($LastInput,StringLen($LastInput)-1))
	EndIf
EndFunc