If we look at MrDEB's remarks, i.e., it doesn't matter if he multiplies by 500/1024 or not and it doesn't matter if the ADC is enabled or not, it's pretty clear that MrDEB doesn't have a clue what value is being read from the ADC.
JimB suggested adding an LCD so he could see what value is being read....but in the past that hasn't worked so well.
I suggested an easy way of using the PICkit 2 GUI's terminal emulator so he could see the value. This is pretty simple to do if you follow the directions and copy&paste a few lines of code.
Easier still, MrDEB could read the ADC and use a for/next loop to toggle an LED the number of times equal to the value read
Some how, MrDEB needs to be able to see the result of the ADC read command. The rest of his code and his deductive reasoning skills aren't up to the task of figuring out what's going on without know what numbers arw being read.