Hi there-not sure if you have done any of the immediate fixes but try to close the safari app.
Force the app to quit by pushing the home button twice to bring up your multi-task bar. This will show all the apps that you have visited. By long pressing the app in question, it will begin to jiggle-press the red circle with the negative sign on the app. It will only quit the app and not delete. Than try to re-open the app and test out.
If that doesn't work, restart the iPad by pressing the power switch down to power off.
Try that and see if that helps.