validation regex with javascript code example

Example: how to validate a string using regular expression in javascript

function validate(){
  var phoneNumber = document.getElementById('phone-number').value;
  var postalCode = document.getElementById('postal-code').value;
  var phoneRGEX = /^[(]{0,1}[0-9]{3}[)]{0,1}[-\s\.]{0,1}[0-9]{3}[-\s\.]{0,1}[0-9]{4}$/;
  var postalRGEX = /^[A-Z]{1,2}[0-9]{1,2} ?[0-9][A-Z]{2}$/i;
  var phoneResult = phoneRGEX.test(phoneNumber);
  var postalResult = postalRGEX.test(postalCode);
  alert("phone:"+phoneResult + ", postal code: "+postalResult);
}