html中的div不会被浏览器执行

I'm making a website and on the profile page, I have a problem with some code there. There is also php used in the page but I don't think that's the problem here. When I load my page on the browser and it is uploaded to my webserver, it does not show the div with the id 'personalinfo', when I look at it with "element inspect", that div does not exist for the browser. I can't find anything wrong in my code.

<!DOCTYPE html>
<?php session_start(); ?>
<html>
<head>
    <title>Minegeekz.com</title>
    <link type="text/css" rel="stylesheet" href="profileStyleSheet.css">
    <style>
       title{
           background: url('<?php $_SESSION['avatar'] ?>') no-repeat;
       }
    </style>
</head>
<body>
   <div id="title">
        <div><h1><?php include 'profileheader.php' ?> </h1></div>
   </div>
   <div id="mid">
        <div class="leftsite">
            <div id="menu">
               <div style="border-top: 0px;">
                    Welcome, <?php include 'welcome.php' ?>
               </div>
               <div>
                   <a href="index.html">Home</a>
               </div>
               <div>
                <?php include 'loginout.php' ?>
            </div>
            <?php include 'registerlink.php' ?>
            <div>
                <a href="About.html">About</a>
            </div>
            <div>
                <a href="contact.html">Contact</a>
            </div>
            <?php include 'forumlink.php' ?>
            <?php include 'profilelink.php' ?>
        </div>
    </div>
    <div id="middle">
        <div id="profilehead">
            <div id="picture">
                <?php include 'avatar.php' ?>
            </div>
            ***<div id="personalinfo">
                <?php echo $_SESSION['fname']; ?><br>
                <?php echo $_SESSION['lname']; ?>
            </div>***
        </div>
    </div>
    <div class="rightsite">
    </div >
</div>
<div id="footer">
    <p>Copyrighted 2015</p>
</div>
</body>
</html>

i think you have declared the url in wrong way check the below code

.title{background: url("<?php $_SESSION['avatar'] ?>") no-repeat;}

Problem solved: I had to change echo $_SESSION['fname']; to echo $_SESSION[fname]; then it works fine. I don't understand why, but it works