var navTimer = null;
var navTimer2 = null;
var navTimer3 = null;

$(document).ready(function() {
    $("#main_options .about_li").hover(
        function() {
            if (navTimer) {
                clearTimeout(navTimer);
                navTimer = null;
            } else
                $("#main_options .about_li ul").slideDown("fast");
				$("#main_options .members_li ul").slideUp("fast");
				$("#main_options .knowledge_centre_li ul").slideUp("fast");
            },
        function() {
                navTimer = setTimeout(
                function() {
                    $("#main_options .about_li ul").slideUp("fast");
					 navTimer = null;
                    },
                    500
                );
        }
    );

	$("#main_options .members_li").hover(
        function() {
            if (navTimer2) {
                clearTimeout(navTimer2);
                navTimer2 = null;
            } else
                $("#main_options .members_li ul").slideDown("fast");
				$("#main_options .about_li ul").slideUp("fast");
				$("#main_options .knowledge_centre_li ul").slideUp("fast");
            },
        function() {
                navTimer2 = setTimeout(
                function() {
                    $("#main_options .members_li ul").slideUp("fast");
					 navTimer2 = null;
                    },
                    500
                );
        }
    );

	$("#main_options .knowledge_centre_li").hover(
        function() {
            if (navTimer3) {
                clearTimeout(navTimer3);
                navTimer3 = null;
            } else
                $("#main_options .members_li ul").slideUp("fast");
				$("#main_options .about_li ul").slideUp("fast");
				$("#main_options .knowledge_centre_li ul").slideDown("fast");
            },
        function() {
                navTimer3 = setTimeout(
                function() {
                    $("#main_options .knowledge_centre_li ul").slideUp("fast");
					 navTimer3 = null;
                    },
                    500
                );
        }
    );

});