Popup window URL suppressed in history

I am popping up a new window via javascript. The URL is going to contain a username/password in it and I am trying to find a way to suppress the URL from being written to the browser history so as to prevent one click access via the history.

Any suggestions as to how to do this?

Why are the username and password in the URL, in the first place? You should use a POST method and not GET to process the login.

It is being passed to a different piece of software that reads the info via variables that can be passed in through the URL.