var timer;
var time = 1000;
$(document).ready(function(){
    
    $('#menu_main').children('li').children(('a')).hover(
    function(e){
        hideSubmenu();
        clearTimeout(timer);
        $parent = $(this).parent();
        $('ul.submenu', $parent).show();
        
    },
    function(e){
        timer = setTimeout('hideSubmenu()', time);
    }
    );
    
    $('ul.submenu').hover(
    function(e){
        clearTimeout(timer);
    }
    
    , function(e){
        timer = setTimeout('hideSubmenu()', time);
    });
});

function hideSubmenu(){
    $('ul.submenu').hide();
}