get and set in javascript object code example

Example: getter and setters in js

var person={firstname:"chetha",secondname="kumar",get fullname()
{
  	return this.firstname+" "+this.secondname;
}
document.write(person.fullname);
var person={firstname:"chethan",secondname="kumar",course:"",set course(x)
{
  	this.course=x;
}
person.course="bca";
document.write(person.course);