Hi, I changed the password of my yahoo email via computer and now I can't send or receive my yahoo email on my blackberry, that is expected.

However, I need to log in to Blackberry Internet Service with a username and password. I have no idea what these are and I have no recollection of even setting them. I tried doing this from a computer and was able to recover my password, but I still don't know what my username is.

Any help?

Nope. Call your carrier and see if they can reset it for you.

Your Web Client email address should be something in the form of xxx would be your user name.