Thanks Melanie, your suggestion worked just fine all working now and giving values between 2 and 19 dependent on the light level. I expect you can also output the Hex or Binary value to the SLCD. Had a hunt around but couldn't figure how to do this.

For Dave: After I posted last night did a bit of night time reading and was looking at the ADCIN section of the manual. However wasn't entirely comfortable with what they were talking about. However, you post was encouragement enough for me to give it a try.

I used the code below (pretty much out of the manual). Then put the light dependent resistor from the Vdd to the RA0/AN0 pin. Before putting the resistor in the reading on the SLCD was all over the place. With the resistor in place it sits at 253 - 254. So I guess I have the right pin. However, If I reduce the light I see no change in the reading.

I am using a PIC18F4620

DEFINE ADC_BITS 8 ' Set number of bits in result (8, 10 or 12)
DEFINE ADC_CLOCK 3 ' Set clock source (rc = 3)
DEFINE ADC_SAMPLEUS 50 ' Set sampling

tone var byte

TRISA = 255 ' Set PORTA to all input
ADCON1 = 0 ' PORTA is analog

:start

ADCIN 0, tone ' Read channel 0 to tone
Serout 0, 6, [$fe, $1] ' Clear screen and move cursor to start of first line
Serout 0, 6, [$1b, $52, 1, #tone] ' Output number value to SLCD.
pause 500

goto start