function emailAFriend() {
  window.open('/email/email_a_friend.ehtml','_blank','height=450,width=500,left=100,top=100,location=no,resizable=no,scrollbars=no,toolbar=no');
}

function setURL() {
  document.getElementById('URL').value = document.referrer;
}

function validateForm(mess1, mess2, mess3, mess4, mess5, mess6) {
  var emailExpr = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

  if (document.getElementById('friend_email').value == "") {
    alert(mess1 + ' ' +  mess2);
    return false;
  }
  else if (!document.getElementById('friend_email').value.match(emailExpr)) {
    alert(mess1 + ' ' +  mess3);
    return false;
  }
  if (document.getElementById('your_name').value == "") {
    alert(mess1 + ' ' +  mess4);
    return false;
  }
  if (document.getElementById('your_email').value == "") {
    alert(mess1 + ' ' +  mess5);
    return false;
  }
  else if (!document.getElementById('your_email').value.match(emailExpr)) {
    alert(mess1 + ' ' +  mess6);
    return false;
  }
  return true;
}