function Employee() {
  this.dept = "HR";
  this.manager = "John Johnson";
}

function printProp() {
  var Ken = new Employee();
  alert(Ken.hasOwnProperty("manager"));
}

People who read this tip also read these tips:

• Forms-based Authentication
• Finding Object Hierarchy
• Creating Tooltips
• Writing Pages without Code Behind
• Advantages of Stored Procedures