iPad login

Has anyone had problems loging in using an iPad. I have a new iPad and been able to login ok over the last three weeks, no problem until now. I must have made 20 or more attempts unsuccesfully. It cannot be email or pasword error as I have just logged in no problems with my PC, three time in succession. On my iPad all that happens is after completing email and password, it comes back to the home screen again no errors are shown. Can anyone help else you will soon see iPad for sale amongst awnings and caravans for salw.