//You should create the validator only after the definition of the HTML form
  var frmvalidator  = new Validator("signup");
  frmvalidator.addValidation("first_name","req","Please enter your First Name");
  frmvalidator.addValidation("first_name","maxlen=50");
  frmvalidator.addValidation("last_name","req","Please enter your Last Name");
  frmvalidator.addValidation("last_name","maxlen=50");
  frmvalidator.addValidation("username","maxlen=50");
  frmvalidator.addValidation("username","req","Please enter a Valid Email Address");
  frmvalidator.addValidation("username","email");
  frmvalidator.addValidation("password","req","Please enter your Password");
  frmvalidator.addValidation("password","minlen=6", "Password must be 6 characters");