In this section:

Centre
GetAtScreenXY (GUI)
SetPosition (GUI)
SetSize (GUI)
BackgroundGraphic property (GUI)
Clickable property (GUI)
ControlCount property
Controls property (GUI)
Height property (GUI)
ID property (GUI)
Transparency property (GUI)
Visible property (GUI)
Width property (GUI)
X property (GUI)
Y property (GUI)
ZOrder property