14Basic operationBasic operationBasic operation ............................ 14Menu operation ............................ 16Keyboards .................................... 17Favourites .................................... 18Contacts ....................................... 22Tone settings ............................... 26Volume settings ........................... 26System settings ........................... 27Basic operationThe centre display has a touch-sensitive surface that allows directinteraction with the screen.mscreen buttonTo return to the next higher menulevel, selectm.Exit screen buttonTo leave the menu currently active,select Exit.Selecting or activating a screenbutton or menu itemTouch a screen button or menu item.The corresponding system function isactivated, a message is shown, or asubmenu with further options isdisplayed.NoticeIn subsequent chapters, theoperating steps for selecting andactivating a screen button or menuitem via the touch screen will bedescribed as "...select