$ _SESSION变量有选择地加载

So, this is a headscratcher. I am submitting a login form via ajax, which is working properly. On login I am setting several $_SESSION variables and loading 3 php files into divs to refresh the data using the user's account info. Here is the javascript:

function processLogin() {
    $.post("/login/index.php" , $("#djloginform").serialize(), 
        function(data) {
            if (data.error == 0) {
                $("#featuredJobs").load("/jobs/featured.php");
                $("#allJobs").load("/jobs/alljobs.php");
                $("#loginbox").load("/login/loggedin-yes.php");
            }
            else {
                alert(data.error);
                $("#djloginemail").val("").focus();
                $("#djloginpassword").val("");
            }
        }, 'json');
}

featured.php and alljobs.php is loading correctly and using the $_SESSION variables, so they are being set correctly and used by 2 out of the 3 php files. Here is the code for what isn't showing:

Logged in as 
<span style="font-weight: bold;">
    <?php echo $_SESSION['djfullname']; ?>
</span>

I just get "Logged in as", but when I refresh the page I get "Logged in as [name]".

The three pages are all using the same exact $_SESSION variables, so I don't know what's going on here. Any ideas?

use session_start(); before echoing $_SESSION['djfullname'].