I have here a simple piece of my autoit script what i wanna do is: when my input is empty the checkbox have to be disabled. and when he is not empty the checkbox have to be enabled. this is my code: #include <ButtonConstants.au3> #include <EditConstants.au3> #include <GUIConstantsEx.au3> #include <WindowsConstants.au3> $Form1 = GUICreate("Form1", 349, 184, 192, 124) $Input1 = GUICtrlCreateInput("", 40, 24, 161, 21) $Checkbox1 = GUICtrlCreateCheckbox("Checkbox1