is_over = 0;
active_el = '';

$(document).ready(function(){
    $("#menu .main_button").hover(
        function(){
			if (active_el != '') active_el.hide();
			is_over = 1;
			active_el = $(this).find('.sub_menu');
			active_el.show();
        },
        function(){
			is_over = 0;
			setTimeout(hide_sub, 300);
        }
    );


	$('.sub_menu').hover(
		function(){
			is_over = 1;
		},
		function(){
			is_over = 0;
			setTimeout(function(){
				hide_sub();
			}, 300);
		}
	);
});


function hide_sub(){
	if (is_over == 1) return;
	$('.sub_menu').hide();
	active_el = '';
}