// isEmailValid
function isEmailValid(emailaddress){
  var checkStr = emailaddress;
  var x = AtSignValid = DoublePeriod = PeriodValid = SpaceValid = 0;

  for (i = 0;  i < checkStr.length;  i++)
  {
	if (checkStr.charAt(i) == '@')
	  AtSignValid++;
	else if (checkStr.charAt(i) == '.')
	{
	  if (x == (i-1) && i != 1)
		DoublePeriod++;
	  else
	  {
		x = i;
		if (AtSignValid == 1)
		PeriodValid++;
	  }
	}
	else if (checkStr.charAt(i) == ' ')
	  SpaceValid ++;
  }
  
  if (AtSignValid != 1 | PeriodValid == 0 | SpaceValid > 0 | DoublePeriod > 0)
	return false;
  else
	return true;	
}

// this function looks for blanks
function isNull(str){
	if (str == ""){
		return true;
	} else {
		return false;
	}
}