function validEmail(email) {
	invalidChars = " /:,;"
	if ((email=="") || (email==null)) {
		return false;
	}
	for (i=0; i<invalidChars.length; i++) {
		badChar = invalidChars.charAt(i)
		if (email.indexOf(badChar,0) > -1) {
			return false;
		}
	}
	atPos = email.indexOf("@",1)
	if (atPos == -1) {
		return false;
	}
	if (email.indexOf("@",atPos+1) > -1) {
		return false;
	}
	periodPos = email.indexOf(".",atPos)
	if (periodPos == -1) {
		return false;
	}
	if (periodPos+3 > email.length) {
		return false;
	}
	return true;
}


// Check that an email address is valid based on RFC 821 (?)
function isValidEmail(address) {
   if (address != '') {
      if (address.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1) return true;
      else return false;
   }
   
   // allow empty strings to return true - screen these with either a 'required' test or a 'length' test
   else return true;
}

// Check that an email address has the form something@something.something
// This is a stricter standard than RFC 821 (?) which allows addresses like postmaster@localhost
function isValidEmailStrict(address) {
   if (isValidEmail(address) == false) return false;
   var domain = address.substring(address.indexOf('@') + 1);
   if (domain.indexOf('.') == -1) return false;
   if (domain.indexOf('.') == 0 || domain.indexOf('.') == domain.length - 1) return false;
   return true;
}