also cant see what the code is meant to achieve because irrespective of whatever value you have for pausetime the led will alsways be at 50% brightness as the on and off times are the same.

If you are trying to get a variable brightness then with pausetime being 0-255 you should have something like

Code:
main:

adcin 0, timeVar

pauseTime = timeVar / 12

high portb.7

pause pauseTime

low portb.7

pause (255-pauseTime)

goto main
which will give a total time of 255 but the on will vary from 0-255 whilst off will also change from 255-0