// Function to check if the email is valid.
function isEmailValid(email, alertMessage)
{
  var atTheRate = email.indexOf("@");
  if (atTheRate < 1)
  {
  	alert(alertMessage);
  	return false;
  }

  var atTheRateRepeat = email.lastIndexOf("@");
  if (atTheRate != atTheRateRepeat)
  {
  	alert(alertMessage);
  	return false;
  }
  
  dot = email.lastIndexOf(".");
  if (dot < 1)
  {
  	alert(alertMessage);
  	return false;
  }
  
  if (dot < atTheRate)
  {
  	alert(alertMessage);
  	return false;
  }
  
  if (dot == email.length - 1)
  {	
  	alert(alertMessage);
  	return false;
  }
  
  if ((atTheRate + 1) == dot)
  {
  	alert(alertMessage);
  	return false;
  }
	
  dotSuccessive =  email.lastIndexOf("..");	
  if (dotSuccessive > atTheRate)
  {
  	alert(alertMessage);
  	return false;
  }
  
  /*if (!isOfCharacters(email, EMAIL_CHARACTER_SET))
  {
  	alert("here" + alertMessage);
  	return false;
  }*/
  return true;
}