working custom widget code with loop inside

<?php
error_reporting(E_ALL);
/*
Plugin Name: Featured Resources
Plugin URI: http://wpguru.in
Description: Featured resources widget for WPGuru.in
Author: Rakesh Raja
Version: 1.0
Author URI: http://wpguru.in
*/

class FeaturedResources extends WP_Widget
{
  function FeaturedResources()
  {
    $widget_ops = array('classname' => 'fearesources', 'description' => 'Featured Resources' );
    $this->WP_Widget('FeaturedResources', 'Featured Resources', $widget_ops);
  }

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

  function update($new_instance, $old_instance)
  {
    $instance = $old_instance;
    $instance['title'] = $new_instance['title'];
    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 $before_title . $title . $after_title;;

    // WIDGET CODE GOES HERE ?>

    <!--resource post-->
<div class="sposts">
<?php
$args = array( 'post_type' => 'resource');
$loop = new WP_Query( $args );
while ( $loop->have_posts()) : $loop->the_post();
if (get_field('featured') == "yes" ) {
echo '<a href="';
the_permalink();
echo '"><div class="spost"><h2>';
the_title();
echo '</h2><div class="left"><img src="';
the_field('thumb');
echo'" alt=""></div><div class="right">';
echo content('100');
echo'<span>Click here to go to read more... </span></div>';
echo'<div style="clear:both;"></div></div></a>';
}
endwhile;
?>
</div>
<!--resource post-->

<?php     echo $after_widget;
  }

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