Connect your GLCD as the schematic in the Unicorn manual has it. (GND the CD3 & 4 lines). Add a couple of 0.1uF caps to the VDD & VSS pins on the 18F4550 if you haven't already.
You have your contrast pot connected incorrectly. Pin 20 is -VEE (out)
the pot should be around 20K and one end to +5, the other to pin 20 and the wiper to pin 3.
i'd made a development board already
just to connect my hardware to the port only
I do not have 20k pot so can i series 2 10k together?
do u mean that the wiper is the center pin of the pot?
so 1st pin is vdd,2nd pin is pin3 and 3rd pin is pin20?
am i correct?