TControl.Left
From OpenEUO
RW Left : n Specifies the X coordinate of the top left corner of a control, relative to its parent or containing control in pixels.
Use the Left property to determine where the left side of the control begins or to reposition the left side of the control. If the control is contained in another control, the Left and Top properties are relative to the parent control. If the control is contained directly by the form, the property values are relative to the form. For forms, the value of the Left property is relative to the screen in pixels.
