atmega 32 interrupts code help

interrupts atmega

hi guys
i am working on a project depends on the car brakes ,battery and seat belt
i made a simulation for the brakes ,and the seat belt by using push buttons
and the car battery by using a switch
but i am facing a problem in the code
i want to display on an LCD if the brakes is pressed or not
, if the seat belt is closed or not
and if the car battery is on or off
so that i used a micro controller atmega32 and used it`s 3 external interrupts pins INT0,INT1,INT2
and make the interrupt occurs at the rising edge but the problem that i wrote code but there is no thing appear on the screen when the push buttons is pressed
here is the code i wrote and the circuit i made
the program checks for the battery if it is on (switch is closed) then it displays battery on then checks the brakes and the seat belt
if the push button switches are pressed it displays (seat belt on)__this in case of seat belt and (brakes on ) ________this in case of brakes
plz i need help?