There are a few easy things to try that will usually fix the problem.
1. Pull the plug on your router. This will most likely fix the problem, as the router is the most common source of the problem. I try and remember to do this once a week anyway, to clear out all the stray bits that start accumulating in it’s routing tables. The router is the little box that often comes from your cable company, or is connected to the cable company’s box. Wait about 45 seconds, then plug the router back in and wait for it boot up and reestablish its connections.
2. Next, reset you iPad. You could just turn off the iPad, but this is a more complete cleanup, and takes no longer. As you may recall from class or from this earlier blog entry, you do this by holding down the power button (on the top right edge of the iPad) and the home button at the same time, continuing to hold until the screen goes black and then the apple appears. At that point you can let go of the buttons and wait for the iPad to reboot, which can take a minute or two. This fixes most problems that originate with the iPad.
3. Turn the iPad’s Wi-Fi off and on. To do this, go to the Settings app, tap on Wi-Fi in the left-hand column, and then in the right-hand column toggle the Wi-Fi switch OFF and then back ON again.
If none of these suggestions help, then take a look at this article, which includes some more things to try.