The right mouse button is used to initiate and control information gathering processes. Intuition uses this button most often for menu operations. For most active windows, pressing the menu button will display the window's menu bar at the top of the screen. Dragging the mouse with the menu button depressed allows the user to browse through the available menus. Releasing the right mouse button over a menu item will select that item, if it is a valid choice. Additionally, the user can select multiple items by repeatedly pressing the select button while the menu button is held down. Drag selection is also available in menu operations. When the menu system is activated, and the user has the menu button pressed, the select button may be pressed and the mouse dragged over all items to be selected. This only works if the select button is pressed after the menu button, and all items that the pointer travels over will be selected. Double clicking the right mouse button can bring up a special requester for extended exchange of information. This requester is called the double-menu requester, because a double click of the menu button is required to reveal it, and because this requester acts like a super menu through which a complex exchange of information can take place. Because the requester is used for the transfer of information, it is appropriate that this mechanism is called up by using the right button. The programmer should consult the Amiga User Interface Style Guide for more information on the standard uses of the mouse and its buttons. Button activation and mouse movements can be combined to create compound instructions. For example, Intuition combines multiple mouse events when displaying the menu system. While the right button is pressed to reveal the menu items of the active window, the user can move the mouse to position the pointer and display different menu items and sub-items. Additionally, multiple presses of the left button can be used to select more than one option from the menus. Dragging can have different effects, depending on the object being dragged. Dragging a window by the drag gadget will change the position of the window. Dragging a window by the sizing gadget will change the size of the window. Dragging a range in a Workbench window will select all of the icons in the rectangular range.