var f = function(x)
{
return x*x;
}
var f = function fact(x)
{
if(x<=1) return 1;
else return x*fact(x-1);
};

function Rectangle(w, h)
{
this.width = w;
this.height = h;
this.area = area;
this.enlarge = Rectangle_enlarge;
this.setSize = setSize;
//通過構造函數定義方法
function Rectangle_enlarge()
{
this.width *= 2;
this.height *= 2;
}
function setSize(width, height)
{
if(arguments.length < 2)
{
throw new Error("arguments less!");
}
else if(arguments.length >= 2)
{
this.width = width;
this.height = height;
}
}
function area()
{
return (this.width * this.height);
}
function area1()
{
alert(10);
}
}