function validEmail(email) {
	var invalidChars = " /:,;";
	
	if (email == "")
		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;
}