function validateEmail(str) {
	if( str == "" ) {
		alert("Empty email address");
		return false;
	}
	if( str.indexOf("@") < 0 ) {
		alert( "Not an email address");
		return false;
	}
	if( str.indexOf("@") > str.lastIndexOf(".") ) {
		alert("Not an email address");
		return false;
	}
	
	if( str.lastIndexOf(".") == str.length-1 ) {
		alert("Not an email address");
		return false;
	}
	return true;
}