var dwProgressBar = new Class({
	
	//implements
	Implements: [Events, Options],

	//options
	options: {
		container: $(document.body),
		boxID:'',
		percentageID:'',
		displayID:'',
		startPercentage: 0,
		displayText: false,
		speed:10,
		step:1,
		allowMore: false
	},
	
	//initialization
	initialize: function(options) {
		//set options
		this.setOptions(options);
		//create elements
		this.createElements();
	},
	
	//creates the box and percentage elements
	createElements: function() {
		var box = new Element('div', { 
			id:this.options.boxID 
		});
		var perc = new Element('div', { 
			id:this.options.percentageID, 
			'style':'width:0px;' 
		});
		perc.inject(box);
		box.inject(this.options.container);
		if(this.options.displayText) { 
			var text = new Element('div', { 
				id:this.options.displayID 
			});
			text.inject(this.options.container);
		}
		this.set(this.options.startPercentage);
	},
	
	//calculates width in pixels from percentage
	calculate: function(percentage) {
		return ($(this.options.boxID).getStyle('width').replace('px','') * (percentage / 100)).toInt();
	},
	
	//animates the change in percentage
	animate: function(go) {
		var run = false;
		if(!this.options.allowMore && go > 100) { 
			go = 100; 
		}
		this.to = go.toInt();
		$(this.options.percentageID).set('morph', { 
			duration: this.options.speed,
			link:'cancel',
			onComplete: this.fireEvent(go == 100 ? 'complete' : 'change', [], this.options.speed)
		}).morph({
			width:this.calculate(go)
		});
		if(this.options.displayText) { 
			$(this.options.displayID).set('text', 'Loaded:' + this.to + '%'); 
		}
	},
	
	//sets the percentage from its current state to desired percentage
	set: function(to) {
		this.animate(to);
	},
	
	//steps a pre-determined percentage
	step: function() {
		this.set(this.to + this.options.step);
	}
	
});