Trying to move comment form to reply

So for the last couple of nights I’ve been trying to get the comments working on a theme I’m working on And finally got nested comments to work. But my problem is when you click the reply button to reply to a comment it just goes to the bottom of the page, what I want to happen is the comment form to jump up under the comment to reply to. I have already tried putting
<?php if ( is_singular() ) wp_enqueue_script( 'comment-reply' ); ?>
above
<?php wp_head(); ?>
in the header.php file. Any help would be greatly appreciated!

Here is my code:
Functions.php

<?php
// Comments Functions
// =======================================================

// Comment Callback
// ================
function custom_comment($comment, $args, $depth) {
   $GLOBALS['comment'] = $comment; ?>

<li <?php comment_class(); ?> id="li-comment-<?php comment_ID() ?>">
   <div class="comment-author vcard">
     <?php echo get_avatar($author_email, $size='48', $default_avatar ); ?>
       <div class="comment-meta"<a href="<?php the_author_meta( 'user_url'); ?>"><?php printf(__('%s'), get_comment_author_link()) ?></a></div>
       <small><?php printf(__('%1$s at %2$s'), get_comment_date(),  get_comment_time()) ?><?php edit_comment_link(__('(Edit)'),'  ','') ?></small>
     </div>
     <div class="clear"></div>

     <?php if ($comment->comment_approved == '0') : ?>
       <em><?php _e('Your comment is awaiting moderation.') ?></em>
       <br />
     <?php endif; ?>

     <div class="comment-text">
         <?php comment_text() ?>
     </div>

   <div class="reply">
      <?php comment_reply_link(array_merge( $args, array('depth' => $depth, 'max_depth' => $args['max_depth']))) ?>
      <?php delete_comment_link(get_comment_ID()); ?>
   </div>
   <div class="clear"></div>
<?php } 

// Add Moderation Links In Comments
// ================================
function delete_comment_link($id) {
  if (current_user_can('edit_post')) {
    echo '<a href="'.admin_url("comment.php?action=cdc&c=$id").'">del</a> ';
    echo '<a href="'.admin_url("comment.php?action=cdc&dt=spam&c=$id").'">spam</a>';
  }
}
?>

Comments.php

<?php

// Do not delete these lines
    if (!empty($_SERVER['SCRIPT_FILENAME']) && 'comments.php' == basename($_SERVER['SCRIPT_FILENAME']))
        die ('Please do not load this page directly. Thanks!');

    if ( post_password_required() ) { ?>
        <p class="nocomments">This post is password protected. Enter the password to view comments.</p>
    <?php
        return;
    }
?>

<!-- You can start editing here. -->

<?php if ( have_comments() ) : ?>
    <h3 id="comments"><?php comments_number('No Responses', 'One Response', '% Responses' );?> to “<?php the_title(); ?>”</h3>

    <ol class="commentlist">
        <?php wp_list_comments('type=comment&callback=custom_comment'); // call custom_comment function ?>
    </ol>
    <div class="clear"></div>
    <div class="comment-navigation">
        <div class="older"><?php previous_comments_link() ?></div>
        <div class="newer"><?php next_comments_link() ?></div>
    </div>
 <?php else : // this is displayed if there are no comments so far ?>

    <?php if ( comments_open() ) : ?>
        <!-- If comments are open, but there are no comments. -->

     <?php else : // comments are closed ?>
        <!-- If comments are closed. -->
        <p class="nocomments">Comments are closed.</p>

    <?php endif; ?>
<?php endif; ?>

<?php if ( comments_open() ) : ?>

<div id="respond">

 <!-- Comment Form Title
============================================================== -->

<h3><?php comment_form_title( 'Leave a Reply', 'Leave a Reply to %s' ); ?></h3>

<!-- end Comment Form Title
============================================================== -->

<div class="cancel-comment-reply">
    <small><?php cancel_comment_reply_link(); ?></small>
</div>

<?php if ( get_option('comment_registration') && !is_user_logged_in() ) : ?>
<p>You must be <a href="<?php echo wp_login_url( get_permalink() ); ?>">logged in</a> to post a comment.</p>
<?php else : ?>

<form action="<?php echo get_option('siteurl'); ?>/wp-comments-post.php" method="post" id="commentform">

<?php if ( is_user_logged_in() ) : ?>

<p>Logged in as <a href="<?php echo get_option('siteurl'); ?>/wp-admin/profile.php"><?php echo $user_identity; ?></a>. <a href="<?php echo wp_logout_url(get_permalink()); ?>" title="Log out of this account">Log out &raquo;</a></p>

<?php else : ?>

<!-- Comment Form
============================== -->

<p><input type="text" name="author" id="author" value="<?php echo esc_attr($comment_author); ?>" size="22" tabindex="1" <?php if ($req) echo "aria-required='true'"; ?> />
<label for="author"><small>Your Name <?php if ($req) echo "(required)"; ?></small></label></p>

<p><input type="text" name="email" id="email" value="<?php echo esc_attr($comment_author_email); ?>" size="22" tabindex="2" <?php if ($req) echo "aria-required='true'"; ?> />
<label for="email"><small>Your Email (will not be published) <?php if ($req) echo "(required)"; ?></small></label></p>

<p><input type="text" name="url" id="url" value="<?php echo esc_attr($comment_author_url); ?>" size="22" tabindex="3" />
<label for="url"><small>Website</small></label></p>

<?php endif; ?>

<!--<p><small><strong>XHTML:</strong> You can use these tags: <code><?php echo allowed_tags(); ?></code></small></p>-->

<p><textarea name="comment" id="comment" cols="100%" rows="10" tabindex="4"></textarea></p>

<p><input name="submit" type="submit" id="submit" tabindex="5" value="Post Comment" />
<?php comment_id_fields(); ?>
</p>
<?php do_action('comment_form', $post->ID); ?>

</form>

<?php endif; // If registration required and not logged in ?>
</div>

<?php endif; // if you delete this the sky will fall on your head ?>

If any one can find my mistake please let me know thanks.