To use CloseGUIObject, you first need to load GUIKit using Needs["GUIKit`"].
CloseGUIObject programmatically initiates a close action (which is normally initiated interactively by user actions such as closing the window).
CloseGUIObject will not necessarily force the removal of all interface resources (like ReleaseGUIObject) if an initial GUIRun has requested that the interface live on past its closing by using the option ReleaseMethod -> Manual.
Use CloseGUIObject instead of ReleaseGUIObject to ensure the original lifecycle intent of a GUIRun call.
EXAMPLES
Basic Examples 
Scope 