If the online form doesn't work for you, the 800 number can be used to subscribe. I have a friend who preferred to call than enroll online.
I was using Levco / Dominion when enrolling with Con-Ed, initially the form seemed off, once I selected state "CT" from the drop down menu, a CL&P option appeared. At that point everything worked fine. The online help shows you where on your bill each piece of information is. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."