I have set a session on a page, but it does not work when it calls on another page. I have tried all possible fixes, but they don't work. I don't know where I am going wrong.

Here is my sample code.

page1.php:

     <?PHP
         $_SESSION['msg'] = "This is a test message";
    ?>

But when it calls on another page, this is not working

    <?PHP
         echo $_SESSION['msg'];
    ?>

Can someone help me to fix this?

php  session