Controls the horizontal positioning of the origin point. By default the menu is absolutely positioning (left aligned) so Menu Horizontal Offset specifies the distance from the left edge of the document (origin) to the menu. With horizontal alignment set to "center" or "right" the origin point moves to the center of the document or to its right edge respectively. Then Menu Horizontal Offset parameter is used to offset the menu to the right (positive value) or to the left (negative value) of the origin. The menu updates its position if browser window is resized.