It may not be that simple. Your mortgage likely has a clause that actually prohibits anyone from "taking it over" (legally called an assumption). You have a few options:
1) Renting the home--either long term or short term to cover your mortgage
2) Putting your home on the market and trying to sell it
3) If you think you owe more than it's worth you can put on market and try to short sale it where bank takes less than your mortgage amount is.
If you need more info on any of this, contact me anytime..email@example.com