[jQuery] get top most parent

[chitgoks]

hi, i am stumped so i am posting it here. no luck searching google for
many hours

this is my html code

<div id="firstpane" class="menu_list"> <!--Code for menu starts here--
>
                <p id="header1" class="menu_head">Header-1</p>
                <div class="menu_body">
                        <a href="#">Link-1</a>
                        <a href="#">Link-2</a>
                        <a href="#">Link-3</a>
                </div>

                <p id="header2" class="menu_head">Header-2</p>
                <div id="header2_menubody" class="menu_body">

                        <div id="pane" class="menu_list">
                                <p id="submenu" class="menu_head">Sub-Menu</p>
                                <div class="menu_body">
                                        <a href="#">Sub Link-1</a>
                                        <a href="#">Sub Link-2</a>
                                        <a href="#">Sub Link-3</a>
                                </div>
                        </div>

                        <a href="#">Link-1</a>
                        <a href="#">Link-2</a>
                        <a href="#">Link-3</a>
                </div>

                <p id="header3" class="menu_head">Header-3</p>
                <div class="menu_body">
                        <a href="#">Link-1</a>
                        <a href="#">Link-2</a>
                        <a href="#">Link-3</a>
           </div>
        </div>  <!--Code for menu ends here-->

if i have access to the object id "header2" how can i get access to
id="submenu" ?
i tried header2obj.children('.menu_head') but it doesnt work. thanks