function Screen(showObjId)
{
	var showObj;	
	var divBack;	
	var docElem;
	var isLoad=true;
    
    function Load()
    {
		docElem=document.documentElement;
		showObj=document.getElementById(showObjId);
		divBack=document.createElement("div");
		
		showObj.style.position="absolute";   
		showObj.style.zIndex="10001";
		showObj.style.display="none";    
	    
		divBack.style.left="0px";
		divBack.style.top="0px";
		divBack.style.position="absolute";
		divBack.style.backgroundColor="#000000";
		divBack.style.filter="alpha(opacity=70)";
		divBack.style.opacity="0.7";    
		divBack.style.zIndex="10000";
		divBack.style.display="none";      	
		
		document.body.appendChild(divBack);
    }
    	
	this.Show=function()
	{
		if(isLoad)
		{
			isLoad=false;
			Load();
		}
		
		divBack.style.width=(docElem.offsetWidth>docElem.scrollWidth?docElem.offsetWidth:docElem.scrollWidth)+"px";
		divBack.style.height=(docElem.offsetHeight>docElem.scrollHeight?docElem.offsetHeight:docElem.scrollHeight)+"px";		
		//divBack.style.display="block";
		divBack.style.display="";
		
		showObj.style.display="";
		showObj.style.left=(docElem.offsetWidth-parseInt(showObj.style.width,10))/2+docElem.scrollLeft+"px";
		showObj.style.top=(docElem.offsetHeight-parseInt(showObj.style.height,10))/2+docElem.scrollTop+"px";		
		//showObj.style.display="block";		
				
	}
	
	this.Hiddle=function()
	{
		divBack.style.display="none";		
		
		showObj.style.display="none";
	}

}