function is_valid_email(email)
{
  return /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/.test(email);
}

function checkEntries(mailform)
{
	if (ralaform.first_name.value == "" || ralaform.last_name.value == "")
	{
		alert('Your name is required.');
		ralaform.first_name.focus();
		ralaform.first_name.select();
		return false;
	}
	if (ralaform.zip.value == "")
	{
		alert('Your zip or postal code is required.');
		ralaform.zip.focus();
		ralaform.zip.select();
		return false;
	}
	if (ralaform.myemail.value == "")
	{
		alert('Your email address is required.');
		ralaform.myemail.focus();
		ralaform.myemail.select();
		return false;
	}
	if (is_valid_email(document.getElementById("email").value) == false)
	{
		alert('Invalid email address.');
		ralaform.myemail.focus();
		ralaform.myemail.select();
		return false;
	}
	else {
		return true;
	}
}