Wordpress how to register admin options

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<?php
add_action( 'admin_init', 'myplugin_admin_init' );

function myplugin_admin_init() {
  //register settings
  register_setting( 'myplugin_options_group1', 'myplugin_option_1' );
}


// create custom plugin settings menu
add_action('admin_menu', 'myplugin_create_menu');

function myplugin_create_menu() {
        if (function_exists('add_options_page')) {
                add_options_page(__('Myplugin Plugin Settings','myplugin'), __('My plugin','myplugin'), 'level_10', __FILE__, 'myplugin_settings_page');
        }
}

function myplugin_settings_page() {
?>
<div class="wrap">
<h2>My Plugins Settings</h2>

<form method="post" action="options.php">
    <?php settings_fields( 'myplugin_options_group1' ); ?>
    <table class="form-table">
        <tr valign="top">
        <th scope="row">Option 1</th>
        <td><input type="text" name="myplugin_option_1" value="<?php echo get_option('myplugin_option_1'); ?>" /></td>
        </tr>
    </table>
    <p class="submit">
    <input type="submit" class="button-primary" value="<?php _e('Save Changes') ?>" />
    </p>
</form>
</div>
<?php } ?>