var dropMenu = Class.create();
dropMenu.prototype =
{
	initialize: function(div_id, opener_class, container_class, dropper_id)
	{
		this.menu_container = $(div_id);
		if( ! this.menu_container ) return false;

		this.hide( this.menu_container );

		this.dropper = $(dropper_id);

		this.all_menus = $A(this.menu_container.getElementsByTagName('div'));

		this.temp_array = new Array();
		this.temp_index = 0;
		this.containers = new Array();
		this.openers = new Array();
		this.selected_branch = -1;
		this.containers_index = 0;
		this.openers_index = 0;
		for( var i=0; i<this.all_menus.length; i++)
		{
			if( this.all_menus[i].id )
			{
				this.matches = this.all_menus[i].id.split('_');

				if( this.matches[0].indexOf('sub') != -1 )
				{
					if( typeof( this.containers[ this.matches[1] ] ) != 'object' )
					{
						this.containers[ this.matches[1] ] = new Array();
					}
					this.containers[ this.matches[1] ][ this.containers_index ] = this.all_menus[i].id;
					this.containers_index++;
				}
				else
				{
					if( typeof( this.openers[ this.matches[1] ] ) != 'object' )
					{
						this.openers[ this.matches[1] ] = new Array();
					}
					this.openers[ this.matches[1] ][ this.openers_index ] = this.all_menus[i].id;
					this.openers_index++;
				}
			}

			if (this.all_menus[i].className != container_class)
			{
				this.temp_array[this.temp_index] = this.all_menus[i];
				this.temp_index++;
			}
		}

		this.all_menus = this.temp_array;

// Changing background color for all menu elements
		for( var i=0; i< this.all_menus.length; i++)
		{
			Event.observe( this.all_menus[i], 'mouseover', this.showMenu.bind(this, this.all_menus[i]) );

			Event.observe( this.all_menus[i], 'mouseout', this.closeMenu.bind(this, this.all_menus[i]) );

			Event.observe( this.all_menus[i], 'click', this.onMenuClick.bind(this, this.all_menus[i]) );
		}

		// set up mouse listener for the dropper
		Event.observe(this.dropper, 'mouseover', this.switchDropperAndContainer.bind(this, 1, 1, 'droper open', 'droper hilite') );
		Event.observe(this.dropper, 'mouseout', this.switchDropperAndContainer.bind(this, 0, 0, 'droper open', 'droper') );

		// set up mouse listeners for the main menu container
		Event.observe(this.menu_container, 'mouseover', this.switchDropperAndContainer.bind(this, 0, 1, 'droper open', 'droper hilite') );
		Event.observe(this.menu_container, 'mouseout', this.switchDropperAndContainer.bind(this, 0, 0, 'droper open', 'droper') );

	},

	switchDropperAndContainer: function( close_all, show, conditional_class, class_name )
	{
		if( close_all ) this.closeAll();

		if( this.dropper.className != conditional_class ) this.dropper.className = class_name;

		if( show ) this.show( this.menu_container );

		if( !show ) this.hide( this.menu_container );
	},

	onMenuClick: function( obj )
	{
		if( obj.firstChild && (obj.firstChild.tagName == 'A') && (obj.firstChild.href != '') )
		{
			this.closeAll();
			document.location.href = obj.firstChild.href ;
		}

		if( (obj.tagName == 'A') && (obj.href != '') )
		{
			this.closeAll();
		}
		return true;
	},

	showMenu: function( obj )
	{
		some_obj = ( obj.tagName == 'A' ) ? obj.parentNode : obj;
		this.setBG( some_obj, 1 );
		some_id = ( some_obj.id ) ? some_obj.id : ( (some_obj.parentNode) ? some_obj.parentNode.id : '' );

		if( some_id && some_id != this.menu_container.id )
		{
			this.matches = some_id.split('_');
			branch_index = this.matches[1];
			menu_level = this.matches[3];

			if( this.selected_branch == -1 )
			{
				this.selected_branch = branch_index;
			}
			if( this.selected_branch != branch_index )
			{
				this.closeAll(this.selected_branch);
				this.selected_branch = branch_index;
			}
			for( var i=0; i < menu_level; i++)
			{
				if( this.containers[branch_index] && this.containers[branch_index][i] )
				{
					this.show(this.containers[branch_index][i]);
					this.setBG(this.openers[branch_index][i],1);
				}
			}
		}

		if( some_id == this.menu_container.id )
		{
			this.closeAll();
		}
	},

	closeMenu: function( obj )
	{
		some_obj = ( obj.tagName == 'A' ) ? obj.parentNode : obj;
		this.setBG(some_obj);
		some_id = ( some_obj.id ) ? some_obj.id : ( (some_obj.parentNode) ? some_obj.parentNode.id : '' );
		if( some_id && some_id != this.menu_container.id )
		{
			this.matches = some_id.split('_');
			branch_index = this.matches[1];
			menu_level = this.matches[3];
			if( this.containers[branch_index] )
			{
				for( var i= menu_level-1; i<this.containers[branch_index].length; i++)
				{
					if(this.containers[branch_index][i] ) this.hide(this.containers[branch_index][i]);
				}
			}
		}
	},

	closeAll: function( branch_number )
	{
		if( typeof (branch_number) == 'undefined')
		{
			for( var i=0; i< this.containers.length; i++)
			{
				if( this.containers[i] )
				{
					for( var j=0; j< this.containers[i].length; j++)
					{
						if( this.containers[i][j] ) this.hide( this.containers[i][j] ) ;
						if( this.openers[i][j] ) this.setBG(this.openers[i][j]);
					}
				}
			}
		}
		else
		{
			if( this.containers[branch_number] )
			{
				for( var k=0; k< this.containers[branch_number].length; k++)
				{
					if( this.containers[branch_number][k] ) this.hide( this.containers[branch_number][k] ) ;
					if( this.openers[branch_number][k] ) this.setBG(this.openers[branch_number][k]);
				}
			}
		}
	},

	setBG: function( element, is_over )
	{
		if( is_over )
		{
			Element.addClassName( element, 'over');
		}
		else
		{
			Element.removeClassName( element, 'over');
		}
	},

	hide: function( element )
	{
		Element.addClassName( element, 'hide' );
	},

	show: function( element )
	{
		Element.removeClassName( element, 'hide' );
	}
};