$(document).ready(function(){
	//display drop arrow for any links with submenu
	$("#nav li:has('ul') a.main").append(' <img src="images/down.png" border="0">');
	
	$('#nav li').hover(function () {
		//show its submenu
			$('ul', this).slideDown();
		}, 
		function () {
			//hide its submenu
			$('ul', this).slideUp(100);			
		}
	);
});