How to remove div in wp_nav_menu

Hello,
I have converted a full featured html5/css3 template into wordpress template. Now in the navigation menu i find it difficult to remove the div tag that is built in wp_nav_menu() function. I saw the codex for wp_nav_menu. There they say you need to add the theme location in functions.php file otherwise wp_nav_menu(array(‘container’ => false )); won’t work. So what is the thing i need to add in functions.php?