var PillMenu = new Class({
		
			//implements
			Implements: [Options,Events],
		
			//options
			options: {
				vertical: 0,
				pillClass: 'pill',
				selectedClass: 'selected',
				duration: 'short',
				transition: Fx.Transitions.Linear
			},
			
			//initialization
			initialize: function(element,options) {
				//set options
				this.setOptions(options);
				//set element
				this.element = document.id(element);
				//set pill element
				this.pill = this.element.getElement('.pill');
				
				if(!this.pill){
				    //build pill element
				    this.pill = new Element('div',{
				    	'class': this.options.pillClass,
				    	'style': 'position:absolute; z-index:1;'
				    });
				    //inject pill into element
				    this.pill.inject(this.element,'top');
				}
				//make effect
				this.pillFx = new Fx.Morph(this.pill, {'duration': this.options.duration, 'link': 'cancel', 'transition': this.options.transition});
				
				this.start();
			},
		
			start: function() {
				//fire event start
				this.fireEvent('start');
				
		        this.element.getElements('li').each(function(el,i){
					//detect selected menu
					if(el.hasClass(this.options.selectedClass)){
						//save selected menu
						this.selected = el;
						//set pill dimensions 
						this.pill.setStyles({
						    width: el.getStyle('width'),
						    height: el.getStyle('height'),
						    left: el.getPosition().x - this.element.getPosition().x,
						    top: el.getPosition().y - this.element.getPosition().y
						});
						
					}						
					
					//add event to element
					el.addEvent('mouseenter', function(){
						//fire event start
						this.fireEvent('change');
						//set effect for horizontal and vertical style
						if(!this.options.vertical){
							this.pillFx.start({
							    'left': [this.pill.getStyle('left'), el.getPosition().x - this.element.getPosition().x],
							    'width': [this.pill.getStyle('width'), el.getStyle('width')] 
							});
						} else {
							this.pillFx.start({
							    'top': [this.pill.getStyle('top'), el.getPosition().y - this.element.getPosition().y],
							    'height': [this.pill.getStyle('height'), el.getStyle('height')]
							});
						}
					
					}.bind(this));
					
				}.bind(this));
		        
		        //add event to reset all
		        this.element.addEvent('mouseleave', function(){
		        	//set effect for horizontal and vertical style
		        	if(!this.options.vertical){
		        		this.pillFx.start({ 
						    'left': [this.pill.getStyle('left'), this.selected.getPosition().x - this.element.getPosition().x],
						    'width': [this.pill.getStyle('width'), this.selected.getStyle('width')]
						});	
					} else {
						this.pillFx.start({ 
						    'top': [this.pill.getStyle('top'), this.selected.getPosition().y - this.element.getPosition().y],
						    'height': [this.pill.getStyle('height'), this.selected.getStyle('height')]
						});	
					}			
					
				}.bind(this));
		
			}
		
		});
		
		/* usage */
		window.addEvent('domready',function() {
			//example for default menu
			var myMenu1 = new PillMenu('menu1');
			//example for vertical menu
			var myMenu2 = new PillMenu('menu2', {vertical: 1});
			//example for elastic menu
			var myMenu3 = new PillMenu('menu3', {
				duration: 'long',
				transition: Fx.Transitions.Elastic.easeOut
			});
			//example for styled menu
			var myMenu4 = new PillMenu('menu4');
			//example for styled menu
			$('link_menu5').addEvent('click',function(e){
				e.stop();
				
				var myMenu5 = new PillMenu('menu5', {
			  		onStart: function() {
						alert('Start');
					},
			  		onChange: function() {
						alert('Change');
					}
				})
			})
			
		});