NEW YORK -- Walmart is testing a new service that lets a delivery person walk into your home when you're not there to drop off packages or put groceries in the fridge.The retailer says the service is for busy families that don't have time to stop at a store. The Bentonville, Arkansas-based company is testing it with a small group of tech-savvy Walmart.com shoppers in California's Silicon Valley who have internet-connected locks.The delivery person is given a one-time code to open the door. Walmart says customers will get an alert on their smartphones when someone enters.Brick-and-mortar retailers, facing increasing competition from online retail giant Amazon, have been working to make online orders easier for shoppers. Wal-Mart Stores Inc., for example, recently teamed up with Google to offer voice-activated shopping.