Username not showing. Can't find error.

<div class="wrap">

    <div id="icon-options-general" class="icon32"></div>
    <h1>The Official Treehouse Badges Plugin</h1>

    <div id="poststuff">

        <div id="post-body" class="metabox-holder columns-2">

            <!-- main content -->
            <div id="post-body-content">

                <div class="meta-box-sortables ui-sortable">

                    <?php if ( !isset( $wptreehouse_username ) || $wptreehouse_username = '' ) :
                    ?>

                    <div class="postbox">

                        <div class="handlediv" title="Click to toggle"><br></div>
                        <!-- Toggle -->

                        <h2 class="hndle"><span>Let's Get Started</span>
                        </h2>

                        <div class="inside">

                            <form name="wptreehouse_username_form" method="post" action="">

                            <input type="hidden" name="wptreehouse_form_submitted" value="Y">

                            <table class="form-table">
                                <tr>
                                    <td>
                                        <label for="wptreehouse_username">Treehouse Username</label>
                                        </td>
                                    <td>
                                        <input name="wptreehouse_username" id="wptreehouse_username" type="text" value="" class="regular-text" />
                                    </td>
                                </tr>

                            </table>

                            <p>
                            <input class="button-primary" type="submit" name="wptreehouse_username_submit" value="Save" />
                            </p>

                            </form>

                        </div>
                        <!-- .inside -->

                    </div>
                    <!-- .postbox -->

                    <?php else: ?>

                    <div class="postbox">

                        <div class="handlediv" title="Click to toggle"><br></div>
                        <!-- Toggle -->

                        <h2 class="hndle"><span>Most Recent Badges</span>
                        </h2>

                        <div class="inside">

                            <P>Below are your 20 most recent badges</p>

                            <ul class="wptreehouse-badges">

                                <?php for( $i = 0; $i < 20; $i++ ): ?>
                                <li>
                                    <ul>
                                        <li>
                                            <img width="120px" src="<?php echo $plugin_url . '/images/wp-badge.png'; ?>">                               
                                        </li>                                       
                                        <li class="wptreehouse-badge-name">
                                            <a href="#">Badge Name</a>
                                        </li>
                                        <li class="wptreehouse-project-name">
                                            <a href="#">Project Name</a>
                                        </li>
                                    </ul>                                   
                                </li>                               
                                <?php endfor; ?>

                                    </ul>

                        </div>
                        <!-- .inside -->

                    </div>
                    <!-- .postbox -->

                    <?php endif; ?>

                </div>
                <!-- .meta-box-sortables .ui-sortable -->

            </div>
            <!-- post-body-content -->

            <!-- sidebar -->
            <div id="postbox-container-1" class="postbox-container">

                <div class="meta-box-sortables">

                    <?php if ( isset( $wptreehouse_username ) || $wptreehouse_username != '' ) :
                    ?>

                    <div class="postbox">

                    <h3><span>Mike the Frog's Profile</span></h3>
                        <div class="inside">

                            <p><img width="100%" class="wptreehouse-gravatar" src="<?php echo $plugin_url . '/images/mike-the-frog.png'; ?>" alt="Mike the Frog Gravatar"></p>

                        </div> <!-- .inside -->

                        <ul class="wptreehouse-badges-and-points">                          

                                <li>Badges: <strong>200</strong></li>
                                <li>Points: <strong>10000</strong></li>

                        </ul>

                        <form name="wptreehouse_username_form" method="post" action="">

                            <input type="hidden" name="wptreehouse_form_submitted" value="Y">

                            <p>
                                        <label for="wptreehouse_username">Username</label>
                            </p>
                            <p>
                                <input name="wptreehouse_username" id="wptreehouse_username" type="text" value="<?php echo $wptreehouse_username; ?>" />       
                                <input class="button-primary" type="submit" name="wptreehouse_username_submit" value="Update" />
                            </p>

                        </form>

                    </div>
                    <!-- .postbox -->

                    <?php endif; ?>

                </div>
                <!-- .meta-box-sortables -->

            </div>
            <!-- #postbox-container-1 .postbox-container -->

        </div>
        <!-- #post-body .metabox-holder .columns-2 -->

        <br class="clear">
    </div>
    <!-- #poststuff -->

</div> <!-- .wrap -->