[Plugin: Category Post Shortcode] how to hide old event from categor post listing

Following is my code

What I am trying to do is if it is event page, display the events that are not past.
Anyone please help?

<?php
/*
Plugin Name: category post shortcode
Plugin URI: http://ibnuyahya.com/wordpress-plugins/category-post-shortcode/
Description: To display post by category in your page/post
Author: ibnuyahya
Author URI: http://ibnuyahya.com/
Version: 1.0
*/

/*
 *
 * How to use
 * =============================================================================
 * just put this shortcode in your post or pages
 *
 *    [cat totalposts="3" category="1,3" thumbnail="true" excerpt="true" ]
 *
 * totalposts - your total number of post to display. default is -1
 * category   - category id. use comma , for multiple id
 * thumbnail  - set true if you want to display thumbnail. default is false
 * excerpt    - set true if you want to display excertp. default is true
 * orderby    - your post will order by . default post_date . check http://codex.wordpress.org/Template_Tags/get_posts for detail
 *
 * thumbnail
 * =============================================================================
 * create custom field key as thumbnail-url and put your thumbnail url in the value area
 *
 * style at your own
 * =============================================================================
 * you need to style your category-post-shortcode plugin in your style.css example

.cat-post{
    width:100%;
}
.cat-post-list{
    display: block;
    margin-bottom: 20px;
    position: relative;

}
.cat-post-images{
    float:left;
    width:140px;
    display:block;
}

.cat-content{
    width:350px;
    float:right;
}
.cat-post-title{
    display: block;
    width:100%;
}
.cat-clear{
    clear:both;
}

 */

function cat_func($atts) {
    extract(shortcode_atts(array(
            'class_name'    => 'cat-post',
            'totalposts'    => '-1',
            'category'      => '',
            'thumbnail'     => 'false',
            'excerpt'       => 'true',
            'orderby'       => 'post_date',
             'order'           => ''
            ), $atts));

    $output = '<div class="'.$class_name.'">';
    global $post;
    $myposts = get_posts("numberposts=$totalposts&category=$category&orderby=$orderby&order=$order");

    foreach($myposts as $post) {

        setup_postdata($post);
        $output .= '<div class="cat-post-list">';
        if($thumbnail == 'true' && get_post_meta($post->ID, 'thumbnail-url',true) != "") {
$output .= '<div class="cat-post-images"><a href="'.get_permalink().'"><img src="'.get_post_meta($post->ID, 'thumbnail-url',true).'" /></a></div>';
        }

      //if category is news
		elseif(get_post_meta($post->ID, 'thumbnail-url',true) == "" && $category != 10){
		$output .= '	<a href="'.get_permalink().'"><div class="date">
			    <div class="date-month">'.get_the_time('M').'</div>
			    <div class="date-day">'.get_the_time('j').'</div>
			</div></a>';
			}

		//if category is event
			elseif(get_post_meta($post->ID, 'thumbnail-url',true) == "" && $category == 10){
			$output .= '	<a href="'.get_permalink().'"><div class="date">
				    <div class="date-month">'.the_event_start_date(null,FALSE,'M'). '</div>
				    <div class="date-day">'.the_event_start_date(null,FALSE,'j').'</div>
				</div></a>';
				}

				$todaysDate = date('m/d/Y');
				$eventDate = the_event_start_date('j F Y');

		// If Category is Event  (Added by Jung Son 28th March 2011)

			   if ($category == 10)  {
        $output .= '<div class="cat-content"><span class="cat-post-title"><a href="'.get_permalink().'">'.get_the_title().'</a></span><br>
<span class="cat-post-date">' .the_event_start_date('j F Y').'</span><br>';
        if ($excerpt == 'true') {
            $output .= '<span class="cat-post-excerpt">
'.get_the_excerpt().'</span> <a href="'.get_permalink().'">read more &raquo;</a>';
        }
		}

		// If Category is NOT EVENT  (Added by Jung Son 28th March 2011)

		else {
			  $output .= '<div class="cat-content"><span class="cat-post-title"><a href="'.get_permalink().'">'.get_the_title().'</a></span><br>
		<span class="cat-post-date">' .get_the_time('j F Y').'</span><br>';

		        if ($excerpt == 'true') {
		            $output .= '<span class="cat-post-excerpt">'.get_the_excerpt().'</span> <a href="'.get_permalink().'">read more &raquo;</a>';
		        }
		}

        $output .= '</div>
            <div class="cat-clear"></div>
        </div>';
    };
    $output .= '</div>';
    return $output;
}

add_shortcode('cat', 'cat_func');

?>