how can i do something like that when i chose option from list then button will be active how to do button2 not active on start gui and it will be active when i chose resolution "user define" from list. and how to back to button2 not active when chose somthing else from lost. $resolution = GUICtrlCreateCombo("", 88, 85, 105, 25, BitOR($CBS_DROPDOWNLIST,$CBS_AUTOHSCROLL)) GUICtrlSetData(-1, "1600x900|1024x768|user define ", "1600x900") $button2 = GUICtrlCreateButton("Define", 404, 383,