function isEmail(id, message) {
	var result = false;
	var element = $(id);
	if(element) {
		var email = element.value;
		email = email.trim().toLowerCase();
		result = email != '' && email.match(new RegExp('^[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-]+@[a-z0-9.-]+\.[a-z]{2,4}$'));
	}
	if(result) {
		element.removeClass('error');
		return true;
	}
	else {
		if(element) {
			element.addClass('error');
		}
		alert(message);
		return false;
	}
}

function isNotEmpty(id, message) {
	var result = false;
	var element = $(id);
	if(element) {
		value = element.value;
		result = value.trim() != '';
	}
	if(result) {
		element.removeClass('error');
		return true;
	}
	else {
		if(element) {
			element.addClass('error');
		}
		alert(message);
		return false;
	}
}