Session variable problems

Ok I have set a session variable to a form field on the previous page. Now I know it set it because I can see it on the next page when I echo it. What I need to do now is make a recordset where username = the session variable. I went through the recorset creation screen and set the field to the user_name session but the recorset dose not display the right records. Why is this. I am using PHP and mySQL.