

Task

Obtain a valid   Y   or   N   response from the keyboard.

The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing   Y   or   N   key-press from being evaluated.

The response should be obtained as soon as   Y   or   N   are pressed, and there should be no need to press an   enter   key.




Key_Purge()                                     // flush keyboard buffer
do {
    #1 = Get_Key("Are you sure? (Y/N): ")       // prompt for a key
    #1 &= 0xdf                                  // to upper case
} while (#1 != 'Y' && #1 != 'N') 