Travel web sites can help you find great bargains on hotel rooms. But when using one, you'll want to take a few steps to make sure you're not getting shortchanged. Some sites, like hotels.com and expedia.com, have fine print that says they can't guarantee requests for a nonsmoking room or two beds for two people. When booking, specify in the comments box why you need what you're asking for. A good example: "I suffer from allergies and my health is going to be affected by a smoking room." It's also a good idea to call the hotel a few days before you arrive, especially if you plan on checking in later in the day when fewer rooms are available. If your room doesn't look right, take the key back to the lobby and call your travel site's customer-service number. "We've gone to lengths to accommodate people," says an Expedia rep, including moving disgruntled customers to another hotel. Keep in mind that the cancellation policies on most of these sites come with nasty fees. Our tip: look for an online bargain first. Then call the hotel for a reservation. "Third-party sites don't always have the best prices," says Linda Sherry of Consumer Action. But even if they do, some hotels might be willing to match them if you ask, according to Joe McInerney, president of the American Hotel and Lodging Association. Then you can have your bargain--and your double beds, too.