Problem with IORD_ALTERA_AVALON_PIO

hi,

i want to write a simple code witch can turn on a led when i press a button.

i have write this piece of code but seems doesn't works...

here is my code:

int main()
{
    volatile long BOUTONS_ON;
 
    while(1)
    {
         BOUTONS_ON = IORD_ALTERA_AVALON_PIO_DAT(KEY_LINE_BASE);
        if ((BOUTON_ON & 0x1) == 0x1)
            {
            Led2_ON();
            }
        else
        {
            Led2_OFF();
 
        }
    }
 
 
  return 0;
}
 

the build works but

the instruction seems to be always true Led2 is always turned ON.

maybe i have missed something or my code must be writted diffrently