Unable to execute routine from external interrupt (miruga27)

Hello,I'm communicating my PIC24FJ1024GB610 to a MRF24J40MA and I'm connecting the INT input to INT1 pin. I've declared the ISR this way: void myISR( void ) __attribute__ ((interrupt_handler));

void myISR( void )
{
TRISAbits.TRISA5=0..