Creating a custom widget

I am trying to create his widget to display person of the month. I am able to save the name in the widget but it doesn’t pass the variable to here: query_posts(‘cat=10&name=Bob&posts_per_page=1’);//works
I want to switch it to say :
query_posts(‘cat=10&name=$person_name&posts_per_page=1’);//doesn’t work

class PersonofMonthWidget extends WP_Widget
{

  function PersonofMonthWidget ()
  {
    $widget_ops = array('classname' => 'PersonofMonthWidget', 'description' => 'Displays Person of Month' );
    $this->WP_Widget('PersonofMonthWidget', 'Person Month', $widget_ops);
  }

  function form($instance)
  {
    $instance = wp_parse_args( (array) $instance, array( 'title' => '' ) );
    $title = $instance['title'];

	$person_name = $instance['person_name'];

?>
  <p><label for="<?php echo $this->get_field_id('title'); ?>">Title: <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo attribute_escape($title); ?>" /></label></p>
   <p><label for="<?php echo $this->get_field_id('person_name'); ?>">Person Name: <input class="widefat" id="<?php echo $this->get_field_id('person_name'); ?>" name="<?php echo $this->get_field_name('person_name'); ?>" type="text" value="<?php echo attribute_escape($person_name); ?>" /></label></p>
<?php
  }

 function update($new_instance, $old_instance)
  {
    $instance = $old_instance;
    $instance['title'] = $new_instance['title'];
	 $instance['person_name'] = $new_instance['person_name'];
    return $instance;
  }

  function widget($args, $instance)
  {
    extract($args, EXTR_SKIP);

    echo $before_widget;
    $title = empty($instance['title']) ? ' ' : apply_filters('widget_title', $instance['title']);

    if (!empty($title))
      echo '<p class="title">' .$before_title . $title . $after_title;

    // WIDGET CODE GOES HERE

query_posts('cat=10&name=Bob&posts_per_page=1');	

if (have_posts()) : ?>
	<?php while (have_posts()) : the_post();echo ':  ';
		 the_title(); echo '<br/>';?></p>
<?php the_post_thumbnail(apply_filters('graphene_excerpt_thumbnail_size', 'thumbnail'));

$content = substr(get_the_content(),0,290);

echo '<p span class="here">'; echo preg_replace ('/\[.*\]/', '', $content); echo '</span></p>';
	endwhile;
endif; ?>

<?php wp_reset_query();

    echo $after_widget;
  }

}
add_action( 'widgets_init', create_function('', 'return register_widget("PersonofMonthWidget");') );?>