Session data lost between pages PHP?

Question

I am making a news add form using post method. In the second page i make data validation. I define the variables like $message = $_POST["message"] and after that $_SESSION['message'] = "$message"; after that I echo the session var and everything look fine the data appear. And when I click to send which go to another page to add the data to the DB the session vars a empty. There is session_start on every page if i define veriable like $_SESSION="test" it passess all 3 pages but the data generated in the form is lost. Please help!