如何将会话值分配给变量

I have a session which I need to assign to a variable to be used on Stored Procedure. But cant seem to get the variable being affected on it

I have already tried the following, but nothing

1)

    ob_start();
    echo $_SESSION['User'];
    $userV = ob_get_contents();
    ob_end_clean();

2)

    $userV =  $_SESSION['User'];

3)

    $userV= echo $_SESSION['User']; //fails as echo, used print instead

4)

    $userV= print $_SESSION['User'];

But when I use a know value like below it works

   $userV= 41;

The intended Procedure as follows:

    $sql="CALL sp_getUser('$userV')";

The second one is the correct one: $userV = $_SESSION['User'];. If $userV does not hold the expected value after this assignment, two things can be the reason: You haven't initialized the session (session_start()) or the you haven't set the $_SESSION["User"] (somewhere in another script you should have something like $_SESSION["User"]=41;.

You can test what is in the $_SESSION-variable presently by print_r($_SESSION);