function Car(color,w,h){
  //通过this来定义--类似java的 public成员
  this.color = color;
  this.width = w;
  this.height = h;
  //通过this来定义--类似java的 private成员
  this.area = function(){return w*h);
}

//example
var c = new Car(red,4,5);
alert(c.color+c.width+c.height);

var area =  c.area();
alert("area="+area);