function is_valid_email(email) {
	var pattern=/^([\w\-\+!#%\*\=\?\^\{\}\|~]+(?:\.[\w\-\+!#%\*\=\?\^\{\}\|~]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
	return pattern.test(email);
}

function is_valid_username(username) {
	var pattern=/^[a-z][a-z0-9]{2,15}$/i
	return pattern.test(username);
}

function validate_field(fieldId,type,msgId,focus) {
	if (!eval("is_valid_"+type+"(document.getElementById('"+fieldId+"').value)")) {
		document.getElementById(msgId).style.display="";
		if (focus)
			document.getElementById(fieldId).focus();
		return false;
	}
	document.getElementById(msgId).style.display="none";
	return true;
}

function validate_equal(fieldId,fieldId2,msgId,focus) {
	if (document.getElementById(fieldId).value!=document.getElementById(fieldId2).value) {
		document.getElementById(msgId).style.display="";
		if (focus)
			document.getElementById(fieldId).focus();
		return false;
	}
	document.getElementById(msgId).style.display="none";
	return true;
}