These samples are intended as a starting point to get going with the MapQuest.js sdk and other APIs.
After creating an account and logging in to the MapQuest Developer Network, click your user name in the upper right corner. Click the Manage Keys link in the left navigation menu or the button in the My Keys section. Here you can click the blue Create a New Key button in the upper right. Give the new key a name, skip the Callback URL (future functionality), and hit Create App. You have a new key that will be ready to roll usually within a minute.
Insert this key into your new code and away you go.