[Solved] Random function without read the Analog 0

I use them to check whenever a user press a push button.

I defined them in this way

#define Power   A0
#define Select  A1
#define Up	A2
#define Down	A3    
#define Left	A4
#define Right	A5

and in setup()

  //Setup the Joystick buttons as inputs
    pinMode(Power, INPUT);
    pinMode(Up, INPUT);
    pinMode(Down, INPUT);
    pinMode(Left, INPUT);
    pinMode(Right, INPUT);
    pinMode(Select, INPUT);

  //Enable pullups on Joystick buttons
    digitalWrite(Power, HIGH);
    digitalWrite(Up, HIGH);
    digitalWrite(Down, HIGH);
    digitalWrite(Left, HIGH);
    digitalWrite(Right, HIGH);
    digitalWrite(Select, HIGH);

and using 6 push buttons between GND and each analog input.
My project is a MP3 player