styling a category page

Hey I’m not sure how to do this was wondering if somebody could help,

I have a parent page showing excerpts from its child page,
I want to style them as a ul with each excerpt as a list item,

But the

<li> are inside just one </li>
<li> of and don't act as separate </li>
<li>

Here is the code,

<ul class="cat">

<li>	<?php
	$child_pages = $wpdb->get_results("SELECT *  FROM $wpdb->posts WHERE post_parent = ".$post->ID."   AND post_type = 'page' ORDER BY menu_order", 'OBJECT'); ?>

	<?php if ( $child_pages ) : foreach ( $child_pages as $pageChild ) : setup_postdata( $pageChild ); ?>
	<h2 class="subpagetitle">

		<a href="<?php echo  get_permalink($pageChild->ID); ?>" rel="bookmark" title="<?php echo $pageChild->post_title; ?>">

<img style="float:left;margin: 0 10px 10px 0;border:1px solid #000;height:90px" src="<?php $child_pages = get_post_custom_values("Image"); echo $values[0]; ?>" alt="thumbnail" height="90" />

<?php echo $pageChild->post_title; ?></a></h2>

	<?php the_excerpt();?>
	<?php endforeach; endif;

	?></li>

</ul>

and the css

ul.cat {
			width:100%;
			display: block;

		padding:20px 0 0 0;

	}

	ul.cat li {
		width:300px;
float:left;

	}

Thanks in advance for your help!