function IsEmailValid(oEmail)
{
	email = oEmail.value
	r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)")
	r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$")
	return (!r1.test(email) && r2.test(email))
}

function checkEmail (oEmail) {
	if ( oEmail != null && oEmail.value != '' ) {
		if (IsEmailValid(oEmail)) {
			return true;
		} else {
			alert ('Please amend your email address.');
		}
	} else {
		alert ('Please put your email address.');
	}
	return false;
}