function validateEmailFormat(sEmail)
{
	var iLength = sEmail.length;

	if (iLength < 5)
		return false;

	var sValidChars = "abcdefghijklmnopqrstuvwxyz0123456789@.-_";

	for (var i = 0; i < iLength; i++)
	{
		var sLetter = sEmail.charAt(i).toLowerCase( );

		if (sValidChars.indexOf(sLetter) != -1)
			continue;

		return false;
	}

	var iPosition = sEmail.indexOf('@');

	if (iPosition == -1 || iPosition == 0)
		return false;

	var sFirstPart = sEmail.substring(0, iPosition);

	sEmail = sEmail.substring((iPosition + 1));

	iPosition = sEmail.indexOf('.');

	if (iPosition == -1 || iPosition == 0)
		return false;

	var sSecondPart = sEmail.substring(0, iPosition);

	var sThirdPart = sEmail.substring((iPosition + 1));

	if(sFirstPart.indexOf('-') != -1)
		return false;

	if(sSecondPart.indexOf('@') != -1 || sSecondPart.indexOf('_') != -1)
		return false;

	if(sThirdPart.indexOf('@') != -1 || sThirdPart.indexOf('_') != -1 || sThirdPart.indexOf('-') != -1 || sThirdPart.length < 2)
		return false;

	return true;
}