Menu button problem

[gsula]

I'm building a small site with Wordpress. One of the menu buttons has three submenus. (e.g. Photos > childhood, wedding, kids) When mouseover this button the submenus drop down. Besides, it also has onclick function as usual. As Photos has no content I don't want it to have this function. I'd like a visitor can only mouseover Photos and choose one of this dropped down childhood, wedding, kids pages.

I use Wordpress theme which already have menu buttons with dropdown submenus. I installed My Page Order plugin as well to arrange my menu buttons.
In header.php of Wordpress Theme folder there is the code <?php wp_list_pages('title_li=&depth=2&sort_column=menu_order'); ?>

What is the solution of this problem?
Thanks in advance.