He's probably hiding with your missing punctuation.
Sorry...had to.
You need to do a thorough search. Start closest to his viv, look high and low, in and under everything, and work your way out. Once you've finished that room, move on to the next, but then, go back and search everything again, starting at the viv and working out. You can put powder (flour, corn starch) on the floor along the walls (snakes like to hug walls) to see if you can find a trail when he moves. You can also make a trap by using an empty liter soda bottle, cutting the top off and inverting it (like a lobster/crap trap) and baiting it with a pinky meal. You can bait another one with a small water dish. Some people have put down tape traps, but that can get quite messy and injure a snake. The main thing is to not give up. People have recovered their escaped snakes weeks and months after the escape. If you have other pets, watch them for they tend to find things before you see it. And don't forget, corn snakes are excellent climbers. Also, try to close any small escape routes out of the room the viv is in (towel under the door, close floor vents, etc).