call bsp in new Session (other username)

Hi experts,

I've the following requirement.

On opening a BSP-Site we have to enter username and password.

Now we would like to open an other bsp-site (don't closing the old one) and make again a login with an other username.

However, now I am not able to login again, as the systems always makes an automatic login with the old one.

Do you know a possibility, to load a BSP-Site in a new browser session?

Thank you very much