传递变量值php

有两个页面，一个是主页面，另一个包含在中

主页

<?php
$var_value = 7;
$_SESSION['varname'] = $var_value;
include 'upload_image.php';
?>

以及包含的页面

<?php
include 'init.php';
if (!logged_in()) {
header('Location: index.php');
exit();
} 
include 'template/header.php';  
?>
<h3>Upload image</h3>
<?php
if (isset($_FILES['image'], $_POST['image_n'], $_POST['image_description'])) {
$image_name = $_FILES['image']['name'];
$bytes = $_FILES['image']['size'];
$image_temp = $_FILES['image']['tmp_name'];
$image_n = $_POST['image_n'];
$image_description = $_POST['image_description'];
$allowed_ext = array('jpg', 'jpeg', 'png', 'gif', 'rar', 'pdf');
//$image_ext = strtolower(end(explode('.', $image_name)));
$image_ext = pathinfo($image_name, PATHINFO_EXTENSION);
$album_id = $_SESSION['varname'];
$errors = array();
if (empty($image_name) || empty($album_id) || empty($image_n) ||         empty($image_description)) {
    $errors[] = 'Something is missing';
} else {
if (strlen($album_name) > 55 || strlen($album_description) > 255) {
        $errors[] = 'One or more fields contains too many characters';
    }
if (in_array($image_ext, $allowed_ext) === false) {
    $errors[] = 'File type not allowed';
}
//if ($image_size > 2097152) {
//  $errors[] = 'Maximum file size is 2mb';
//}
if (album_check($album_id) === false) {
    $errors[] = 'Couldn''t upload to that album';
}
}
if (!empty($errors)) {
    foreach ($errors as $error) {
        echo $error, '<br />';
    }
} else {
    $byte = formatSizeUnits($bytes);
    upload_image($image_temp, $image_ext, $album_id, $image_n, $image_description, $byte);
    header('Location: view_album.php?album_id='.$album_id);
    exit();
}
}
$albums = get_albums();
if (empty($albums)) {
echo'<p>You don''t have any albums. <a href="create_album.php">Create an album</a></p>';
} else {
?>
<form action="" method="post" enctype="multipart/form-data">
<div class="choose">
    <p>Choose a file:<br /><input type="file" name="image" /></p>
    </div>
        <div class="des">
        <p>Name*:<br /><input type="text" name="image_n" maxlength="55"/></p>
        <p>Description*:<br /><textarea name="image_description" rows="6" cols="35" maxlength="255"></textarea></p>

    <p><input type="submit" value="Upload" /></p>
    </div>
</form>
<div class="foot">
<?php   
}
include 'template/footer.php';  
?>
</div>

第二页末尾的表单没有加载。。但是当我删除主页面的第一行$var_value＝7时；末端荷载的形式。。我不知道问题出在哪里，或者有其他方法可以在main中设置相册值并将其传递到包含的页面