AT90S8545 ADC problem

[Yannick De Wit]

i try to use the internal ADC with the AT90S8584 but i just can't get it to
work , value is always 0 , i tested if he jumps to the interrupt routine and
this works but he doesn't read the ADC register !!! this is my interrupt
service routine :

//AD convertor registers
ADMUX = 0x00; //select port a0
ADCSR = 0xEF; // free running mode and full prescaling

interrupt [ADC_INT] void adc_isr(void) {

if (ADMUX == 0x01)

{
value = ADCW; //value from port a0
ADMUX = 0x00;
}

else

{
value2 = ADCW; //value from port a1
ADMUX = 0x01;
}

}

thanks for the help

Yannick