Display random products from category on homepage in magento

first make a file and path is-->app\design\frontend\default\default\template\catalog\random.phtml
 paste below given code:

 <?php
$chosen_category = Mage::getModel('catalog/category')->load($this->getCategoryId());
$_productCollection = $this->getLoadedProductCollection();
$number_of_products = $this->getNumProducts();
if (sizeof($_productCollection) < $number_of_products) {
    $number_of_products = sizeof($_productCollection);
}
$displayed_products = array();
foreach ($_productCollection as $_product) {
    $displayed_products[] = $_product;
}
$random_products = array();
if (sizeof($_productCollection) > 1) {
    $random_products = array_rand($displayed_products, $number_of_products);
} else {
    $random_products = array('0');
}
?>
<?php if(!$_productCollection->getSize()):?>
<div class="note-msg">
    <?=$this->__('There are no products matching the selection.')?>
</div>
<?php else:?>

<div class="main-binder">
  <div class="cms-box">
  <div class="category-title">
      <h2>Random Products</h2>
  </div>  
  <div class="category-products">
    <table id="products-grid-table" class="products-grid">
    <?php
    $k=0;
    for ($i=0; $i < $number_of_products; $i++): ?>
    <?php if ($k == 0) { ?>
            <tr class="first odd">
        <?php } if($k==3)    { $k=0;  ?>
            </tr><tr class="first odd even">
        <?php } ?>
            <td id="td_<?php echo ($k+1); ?>" <?php if($k==3){ ?>class="last"<? } ?> >
        <div class="cms-box">
              <div id="cont_<?php echo ($k+1); ?>">
              <div class="product-name-block">               
                  <?php
                  $pname=$this->htmlEscape($displayed_products[$random_products[$i]]->getName());
                  ?>
                  <h3 class="product-name">                
                  <a href="<?php echo $displayed_products[$random_products[$i]]->getProductUrl()?>" title="<?php echo $pname; ?>">
                    <?php if(strlen($pname) > 28) {echo substr($pname,0,25)."...";}else {echo $pname;}?>
                    </a></h3>
                </div>
                <div class="image-box">               
                <a class="product-image" href="<?php echo $displayed_products[$random_products[$i]]->getProductUrl()?>"> <img src="<?php echo $this->helper('catalog/image')->init($displayed_products[$random_products[$i]], 'small_image')->resize(140);?>" alt="<?php echo $this->htmlEscape($displayed_products[$random_products[$i]]->getName())?>" title="<?php echo $this->htmlEscape($displayed_products[$random_products[$i]]->getName())?>"/> </a>
                </div>

                <div class="cms-price-box" style=" text-align:center;">
                    <span class="regular-price" id="product-price-37">                      
                        <span class="price" ><?php echo Mage::app()->getLocale()->currency(Mage::app()->getStore()->
     getCurrentCurrencyCode())->getSymbol().$displayed_products[$random_products[$i]]->getPrice(); ?></span>
                    </span>                    
                </div>
                <div class="button-row" style="text-align:center;">
                            <button onclick="setLocation('<?php echo $displayed_products[$random_products[$i]]->getProductUrl();?>')" class="button" type="button"><span><span><span>Details</span></span></span></button>                                                                                                                          
                    <button onclick="setLocation('<?php echo $this->getUrl('')."/checkout/cart/add?product=".$displayed_products[$random_products[$i]]->getId()."&qty=1"  ?>')" class="button"><span><?php echo $this->__('Add to Cart') ?></span></button>
                </div>
              </div>
        </div></td>  

<?php $k++; ?>
<?php endfor;?>
</tr>
      </table>   
    </div>
  </div>
</div>      
<?php endif;?>

  

paste below Xml code in whre you want random product(like home page,any one page)

{{block type="catalog/product_list" category_id="59" num_products="4" template="catalog/random.phtml"}}