function BlackScreen(){
	this.intervalID;
	this.root;
	
	this.init();
}

BlackScreen.prototype = {
    constructor: BlackScreen,
	
	init: function(){
		var root = document.createElement("div");
		root.align = "center";
		root.className = "bs_root";                
                root.style.height = getPageSize()[1]+"px";
		document.body.appendChild(root);
		
		var darkLevel = 0;
		
		var getDarker = function(){
			if(darkLevel != 4){
				root.style.backgroundImage = "url(_images/bsbg"+ (++darkLevel) +".png)";
			}else{
				clearInterval(this.intervalID);
			}
		}
		
		this.intervalID = setInterval(getDarker, 35);
		
		this.root = root;
	}, 
	
	getRoot: function(){
		return this.root;
	}
}