BODY_OVERFLOW='';
EFFECT=function(){
	
}

EFFECT.prototype.setOpacity=function(obj,value){
	if (typeof obj !='Object'){
		obj=document.getElementById(obj);
	}
	obj.style.opacity = value/10;
	obj.style.filter = 'alpha(opacity=' + value*10 + ')';
}

EFFECT.prototype.night=function(moonphase){
	if (typeof moonphase=='undefined'){
		moonphase=2;
	}
	if (document.body.style.overflow){
		BODY_OVERFLOW=document.body.style.overflow;
	}else{
		BODY_OVERFLOW='scroll';
	}
	//document.body.style.overflow='hidden';
	oDiv=document.createElement('div');
	oDiv.style.height='100%';
	oDiv.style.width='100%';
	oDiv.style.background='black';
	oDiv.style.opacity = moonphase/10;
	oDiv.style.filter = 'alpha(opacity=' + moonphase*10 + ')';
	oDiv.style.position='absolute';
	oDiv.style.top='0px';
	oDiv.style.left='0px';
	oDiv.style.zIndex=200;
	oDiv.id='NIGHT_SHADE';
	document.body.appendChild(oDiv);
}
EFFECT.prototype.day=function(){
	document.body.style.overflow=BODY_OVERFLOW;
	document.getElementById('NIGHT_SHADE').parentNode.removeChild(document.getElementById('NIGHT_SHADE'));
}

$Effect=new EFFECT;