// JavaScript Document

//NO.1
function addEvent(obj,type,fn)
{
	if(obj.addEventListener)
		obj.addEventListener(type,fn,false);
	else if (obj.attachEvent)
	{
		obj["e"+type+fn] = fn;
		obj[type+fn] = function(){obj["e"+type+fn](window.event);}
		obj.attachEvent("on"+type,obj[type+fn]);
	}
}

//NO.2
function removeEvent(obj,type,fn)
{
	if(obj.removeEventListener)
		obj.removeEventListener(type,fn,false);
	else if (obj.detachEvent)
	{
		obj.detachEvent("on"+type,obj[type+fn]);
		obj[type+fn] = null;
		obj["e"+type+fn] = null;
	}
}


//NO.4
function doSomething(e){
	if(!e) var e = window.event;
	alert(e.type);
	}
	
//NO.5
var x,y;
if (self.innerHeight) //all except Explorer
{
	x = self.innerWidth;
	y = self.innerHeight;
	}
else if (document.documentElement && document.documentElement.clientHeight)
	//Explorer 6 Strict Mode
{
	x = document.documentElement.clientWidth;
	y = document.documentElement.clientHeight;
	}
else if (document.body) //other Explorers
{
	x = document.body.clientWidth;
	y = document.body.clientHeight;
	}