Problem with Creating Theme Options page

Hi I m trying to create a theme options page but cannot manage to get the variable output in my front end, something must be off, can anyone help me out.

This is the code I have in my functions.php

add_action('admin_menu', 'add_theme_options');

function add_theme_options() {
    add_theme_page(__('Sidebar Banner'), __('Sidebar Banner'), 'edit_themes', basename(__FILE__), 'mitc_banner_url');
}

function mitc_banner_url() {
    if (isset($_POST['option_submit'])) :
        update_option('banner_url', $_POST['linkurl']);
        echo '<div id="message" class="updated fade"><p><strong>'.__('Options saved.').'</strong></p></div>';
    endif;
?>

<div class="wrap">
     <form id="options_form" method="post" action="">
        <h2><?php _e('Banner Link URL'); ?></h2> 

        <div class="ui-sortable">
            <div class="postbox">
                <h3 class="hndle"><php _e('Sub Header'); ?></h3>
                <div class="inside">

                    <div style="padding:10px;">
                        <div>
                            <label for="linkurl">Banner Link URL</label>
                            <input style="width:500px" id="linkurl" />
                        </div>
                        <div class="submit">
                            <input type="submit" name="option_submit" id="option_submit" value="Update Options" />
                        </div>

                        <?php
                        ?>
                    </div>

                </div>
            </div>
        </div>
    </form>
</div>

<?php } ?>

and this one in my front end:

<?php
					   if (get_option("banner_url"))
					   $banner_url = get_option("banner_url");
					   echo $banner_url;
					   ?>