HELP: Drop down menu

Hey guys,
I am having a little trouble setting up a drop down menu for my webpage. (www.astonlife.co)
i am using theme “mumrik”, which is no longer supported… and as you can see on the navigation menu the sub-menu doesn’t show as a dropdown menu, but it actually shows as a side bar bellow the slide-show (ex: “seguros de vida” )
I looked at the code in header.php for the navmenu and this is all i have

<div id="MainNavigation">

<ul>
		<!-- Add Config for Home -->
		<!--
<li><a<?php if(is_home()){?> class="current"<?php }?> href="<?php bloginfo('url'); ?>/">Home</li>
-->
		<?php wp_list_pages('title_li=&child_of=0&depth=1' ); ?>
		</ul>

which makes it even harder!!

Can someone please help me getting a code for it??
I’d appreciate it, thanks ??

[Moderator Note: Please post code or markup snippets between backticks or use the code button.]