Why are Session Variables carried over into a brand new browser window?

This is my first posting to this group, so I am not familiar with any special etiquette for it, please bear with me. . . I maintain the PHP code for the website for the murals of Winnipeg and have found a situation where I have a session open with the state of the user's search results saved in the session and link to a location with the following link: <A target="blank" href="http://www.themuralsofwinnipeg.com/Mpages/index.php?action=gotomural&m uralid=179"> so this opens a new browser window, but it is inheriting the session values from the browser window that called it and is causing problems in the new window. When I open a new browser window shouldn't it start a whole new session and not get anything from the previous browser. Thanks in advance for your help, Bob Bruce, Winnipeg, Manitoba Canada