How to catch users which open application from multiple page

Question

In my web application, some users open app in multiple browser page. How can I catch users when they do it?

Edit about why I need such this thing: I have a variable named DealerID, carried between pages with session. Some users want that: "While I make my jobs with a DealerID in one page, make other jobs with another DealerID on another page"

I tried to explain. I hope, it will help.

Answer 1

The real thing you need to focus on is fixing your application to support multiple tabs/pages.

What I suggest you do is store the session data into the page of the application and reconstruct it when the page submits it back to the server. That way each page can use the same session variables to pass the page along, without it creating side effects in the system.

Session data really should be truly global data, that can be referenced without worry. If you have "long persisting" data that is created with the assumption that only one page will ever be using it, then you are going to have some trouble.