Adding my own simple JavaScript in menu nav

Hi, I want to use my own simple JavaScript where when user clicks a menu item, it changes background-color, but since I’m pulling my list from WP db, how the heck do I add something like:

<div id=”menu_item_1″ onclick=”changeBgColor(“menu_item_1″)”>…</div> and I want to add this for each menu item but I have this in my header.php:

<div class=”menuItems”>
<?php wp_list_pages(‘title_li=&sort_column=menu_order’); ?>
</div><!– END menuItems–>

I’m using wp_list_pages rather than hardcode my menu items, so how do I do this? Please anyone, thanks!