function menu_navigation(menus)
{
	this.menus = menus;
	this.dd = '_dropdown';
	this.button = '_button';
	this.image_path = 'images/nav/';

	this.arrow_path = 'images/arrow.gif';

	this.timeout = '';

	var self = this;

	this.hide_all = function()
	{
		this.menus.each(function(menu){
			$(menu+self.dd).style.display = 'none';
			$(menu+self.button).src = self.image_path+'nav_'+menu+'.png';
		});
	}

	this.show = function(target)
	{
		this.clear_timeout();

		this.hide_all();

		$(target+self.dd).style.display = 'block';
		$(target+self.button).src = self.image_path+'nav_'+target+'_over.png';
	}

	this.clear_timeout = function()
	{
		if( this.timeout )
		{
			clearTimeout(this.timeout);
		}
	}

	this.hide_delay = function()
	{
		this.timeout = setTimeout('mNav.hide_all()',300);
	}

	this.show_arrow = function(obj)
	{
		obj.parentNode.style.backgroundImage = 'url('+this.arrow_path+')';
	}

	this.hide_arrow = function(obj)
	{
		obj.parentNode.style.backgroundImage = '';
	}
}