The Show Phone Screen option only applies to the A-menu screens accessed when you press the 
key. If the option is on, if you receive a call while in the A-menu, the phone will automatically exit the menus and display the call details.
To turn show phone screen on/off: (9504/9508)
1.Press the MENU button.
2.Use the 
up and down 
arrow keys to locate the option Call Settings.... Press the Select soft key.
3.Use the up and down arrow keys to locate the option Show Phone Screen.
4.Use the 
left and right 
arrow keys or press the On/Off soft key to change the setting.
5.When completed, press the Done soft key.
6.Press the Exit soft key to exit the menus.