multiple session issue

Hi,

I have created SAP transaction ivews in my portal with SAP Logon tickets to connect r/3. End users are having tendency to open multiple browser window using Ctrl+N. This way they dont have to login many times and can have many portal window open.

The problem here is for each new window opned with Ctrl+n it opens a new session in R3. this way there are so many sessions are opened in R3. Is there any way we can prevent multiple sessions in R3?