Random Post from a category

I have looked around the forums before posting. I want to display a random post from a single category say “life”. How to achieve it? I am a zero at php. currently i am using the following lines of code.

<div id="content">
<!--Get the last post from Life category. -->

<?php query_posts('category_name=Life&showposts=1'); ?>
<!-- Start Stylyzing Prdoduct -->
<?php while (have_posts()) : the_post(); ?>

<h1><?php the_category(' '); ?></h1>

<?php the_title('<h2>', '</h2>'); ?>
<?php the_excerpt(); ?>

<?php endwhile;?>

this code shows the latest from the life category. how to get a random post from life category?

Thanks in advance

//Techmulla