Joel has given you excellent advice. Another thing to try is strained baby veggies, like Gerber Nature's Harvest. He may eat some off of a baby spoon for you.
The best way to know whether or not he's eating is to examine poops. They should be firm and have 3 seperate components: clear (urates) white and either brown or green solids. If you aren't seeing droppings, he's simply not eating properly.
In the future, I advise you to place an order for Lactated Ringers solution from
www.avitec.com. They will sell you the syringes and solution without a prescription. However, its really too late for that now. It would take too long for it to get to you for this case. Again, keep him warm and away from drafts.
THE OUTLAW