If you'd like to simulate the circuit, first install PSpice from Orcad, or download my local copy (version 9.1) if that's not available. I really don't feel like drawing the circuit so that it will simulate in PSpice, but I can show you how to get a varying voltage source. Grab this file, which demonstrates how to set up the circuit analysis to vary a DC voltage source (i.e., the entire LM317T circuit). Here's a screen shot of it:
Be sure and look at Analysis > Setup > DC Sweep to see how I make the DC voltages source vary its voltage. Here's screen shot of the analysis setup dialog:
