@grumpy1stephen: If you cannot sign in to eBay then what I would suggest would be to click on the Reset Your Password link at the bottom of the sign-in page (see screenshot between the first and second paragraph of this reply for details). That way you ought to receive a link to reset your password on the e-mail address that is linked to the account which you cannot sign in with.
Once you receive the link to reset your password, think of a new password that you've never used before on any of your online accounts, then reset the password. If possible try to think of a new password containing a mixture of lower and upper case letters, numbers and symbols - ideally something that you can remember as easily as you can remember your name - as that way you'll be less likely to forget it and can just log in easily when you want to. Longer, more complex passwords also have the advantage in that they're far more difficult for hackers to successfully work out and use in order to gain unauthorised access to your account.
