Left SHIFT + Right ALT + DEL : master reset Blackberry, Press & Hold them until LCD swithed off and red blinking LED. Remember, all your data in the phone will be lost..
ALT + Right SHIFT + DEL : Restart blackberry without release the battery, that functioned t refresh memory or to configure after installing an application.
On home screen, press ALT and follow ‘LGLG‘, event log displayed. After that step you can press HOME and choose CLEAR LOG. This code fonctioned to clear Log.
Same as your PC, you can jump to the other application. ALT + TAB n your PC, on Blackberry press ALT + ESC.