Get Post With Thumbnail help

hello , i am using newshun theme
but i wanna add A New section , and call Latest 1 Topic from selected category
i guess everything is fine , and i can call my post
but i need support to show Large thumbnail to the Post in home page

this is my site :
http://www.uppicza.com/image-EC20_4C241354.jpg

my index.php is :

<?php if ((!function_exists(“check_theme_footer”) || !function_exists(“check_theme_header”))) { ?><?php { /* nothing */ } ?><?php } else { ?>

<?php get_header(); ?>

<div id=”content”>

<?php $featured_slider_activate = get_theme_option(‘featured_activate’); if(($featured_slider_activate == ”) || ($featured_slider_activate == ‘No’)) { ?>
<?php { /* nothing */ } ?>
<?php } else { ?>
<?php if((is_home())&& ($paged < 1)) { ?>
<?php include (TEMPLATEPATH . ‘/featured.php’); ?>
<?php } ?>
<?php } ?>

<?php $featured_category_active = get_theme_option(‘featured_category_activate’); if(($featured_category_active == ”) || ($featured_category_active == ‘No’)) { ?>
<?php { /* nothing */ } ?>
<?php } else { ?>
<?php if(is_home()) { ?>
<?php include (TEMPLATEPATH . ‘/featured-category.php’); ?>
<?php } ?>
<?php } ?>

<?php if(is_home()) { ?>
<div id=”postbox”>
<div id=”postinner”>
<?php } else { ?>
<div id=”postwidth”>
<?php } ?>

<div id=”post-entry”>
<?php include (TEMPLATEPATH . ‘/headline.php’); ?>

<?php $postcounter = 1; if (have_posts()) : ?>

<?php while (have_posts()) : $postcounter = $postcounter + 1; the_post(); $do_not_duplicate = $post->ID; $the_post_ids = get_the_ID(); ?>

<div class=”post-meta” id=”post-<?php the_ID(); ?>”>

<?php $values = get_post_custom_values(“post-img”); if (isset($values[0])) : ?>

<?php $timthumb_activate = get_theme_option(‘timthumb_activate’); if($timthumb_activate == ‘Yes’) { ?>

” title=”<?php the_title(); ?>”><img src=”<?php echo bloginfo(‘template_url’); ?>/scripts/timthumb.php?src=<?php $values = get_post_custom_values(“post-img”); echo $values[0]; ?>&w=<?php $thumbwidth = get_theme_option(‘thumb_width’); if($thumbwidth == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbwidth); ?><?php } ?>&h=<?php $thumbheight = get_theme_option(‘thumb_height’); if($thumbheight == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbheight); ?><?php } ?>&zc=1&q=100&cropfrom=<?php $thumbcrop = get_theme_option(‘timthumb_cropping’); if($thumbcrop == ”) { ?>topcenter<?php } else { ?><?php echo stripcslashes($thumbcrop); ?><?php } ?>” alt=”<?php the_title(); ?>” class=”alignright” />

<?php } else { ?>

” title=”<?php the_title(); ?>”><img src=”<?php $values = get_post_custom_values(“post-img”); echo $values[0]; ?>” alt=”<?php the_title(); ?>” width=”<?php $thumbwidth = get_theme_option(‘thumb_width’); if($thumbwidth == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbwidth); ?><?php } ?>” height=”<?php $thumbheight = get_theme_option(‘thumb_height’); if($thumbheight == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbheight); ?><?php } ?>” class=”alignright” />

<?php } ?>

<?php else: ?>

<?php $timthumb_activate = get_theme_option(‘timthumb_activate’); if($timthumb_activate == ‘Yes’) { ?>

” title=”<?php the_title(); ?>”><img src=”<?php echo bloginfo(‘template_url’); ?>/scripts/timthumb.php?src=<?php echo get_post_image(); ?>&w=<?php $thumbwidth = get_theme_option(‘thumb_width’); if($thumbwidth == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbwidth); ?><?php } ?>&h=<?php $thumbheight = get_theme_option(‘thumb_height’); if($thumbheight == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbheight); ?><?php } ?>&zc=1&q=100&cropfrom=<?php $thumbcrop = get_theme_option(‘timthumb_cropping’); if($thumbcrop == ”) { ?>topcenter<?php } else { ?><?php echo stripcslashes($thumbcrop); ?><?php } ?>” alt=”<?php the_title(); ?>” class=”alignright” />

<?php } else { ?>

” title=”<?php the_title(); ?>”><img src=”<?php echo get_post_image(); ?>” alt=”<?php the_title(); ?>” width=”<?php $thumbwidth = get_theme_option(‘thumb_width’); if($thumbwidth == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbwidth); ?><?php } ?>” height=”<?php $thumbheight = get_theme_option(‘thumb_height’); if($thumbheight == ”) { ?>100<?php } else { ?><?php echo stripcslashes($thumbheight); ?><?php } ?>” class=”alignright” />

<?php } ?>

<?php endif; ?>

<div class=”entry”>
<h1>” rel=”bookmark” title=”<?php the_title(); ?>”><?php the_title(); ?></h1>

<?php the_post_excerpt(); ?>

</div><!– ENTRY END –>

<?php $get_google_activate = get_theme_option(‘adsense_loop_activate’); if(($get_google_activate == ”) || ($get_google_activate == ‘Disable’)) { ?>
<?php } else { ?>
<?php $get_google_code = get_theme_option(‘adsense_loop’); if($get_google_code == ”) { ?>
<?php } else { ?>
<?php if($postcounter <= 4){ ?>
<div class=”adsense-loop”>
<?php echo stripcslashes($get_google_code); ?>
</div>
<?php } ?>
<?php } ?>
<?php } ?>

<div class=”clearfix”></div>
</div><!– POST META <?php the_ID(); ?> END –>

<?php endwhile; ?>

<?php else : ?>

<p class=”center”>غير موجود</p>

<p class=”center”>عفواً، ولكنك تحاول البحث عن شئ غير موجود هنا.</p>

<?php endif; ?>

<div class=”clearfix”></div>
</div><!– POST ENTRY END –>

<?php include (TEMPLATEPATH . ‘/paginate.php’); ?>

<?php if(is_home()) { ?>
</div><!– POSTINNER END –>
</div><!– POSTBOX END –>
<?php } else { ?>
</div><!– POSTWIDTH END –>
<?php } ?>

<div class=”clearfix”></div>
</div><!– CONTENT END –>
<div id=”sidebar”>
<div id=”sidebarinner”>
<ul class=”sidebar_list”>
<li class=”widget_categories”>
<h6>احدث المقابلات</h6>
<?php query_posts(‘category_name=interview&showposts=1’); ?>
<?php while (have_posts()) : the_post(); ?>

• “>
  <?php the_title(); ?>
  <?php while (have_posts()) : the_post(); ?>
  

<?php endwhile; ?>

</il>

</div>
</div>
<?php endwhile; ?>

<?php get_sidebar(); ?>

<?php get_footer(); ?>

<?php } ?>

what i should change to call post thumbnail with dimension ?
335×250