function changeDefaultValue(sender, default_value, change_value, classN)
	{
		if (sender.value == default_value)
		{
			sender.value = change_value;
			sender.className = classN;
		}
	}
	
	//headnav js 
	function showHideChild(sender, visib, classN)
	{
		var obj = sender.getElementsByTagName('p');
		sender.className = classN;
		obj[0].style.visibility = visib;
	}
	
	function getItemMenu()
	{
		var obj = document.getElementById('headnav').getElementsByTagName('p');
		
		for (var i = 0; i < obj.length; i++)
		{
			var par = obj[i].parentNode;
			
			par.onmouseover = function() {showHideChild(this, 'visible', 'hover');}
			par.onmouseout = function() {showHideChild(this, 'hidden', '');}
		}
	}
	
	//addEvent 
	function addEvent(obj, handler, callback, capture)
	{
		try
		{
			obj.addEventListener(handler, callback, capture);
		}catch(e)
		{
			obj[handler + callback] = function()
			{
				callback.call(obj);
			}
			
			obj.attachEvent('on' + handler, obj[handler + callback]);
		}
	}
	
	addEvent(window, 'load', getItemMenu, false);