function login_checker(){
  if (!document.login_form.email_address.value.match(/^[a-z0-9]+[_.a-z0-9-]+@[a-z0-9-]+\.+[a-z0-9.-]+$/i))
  {
    alert("Please enter your email address. It must be a valid email address.");
    document.login_form.email_address.focus();
    return false;
  }
  if (document.login_form.password.value == "")
  {
    alert("Please enter your password. If you have forgotten your details simply click the 'Forgot Password?' link and we'll send you a reminder.")
    document.login_form.password.focus()
    return false
  }
    document.login_form.submit()
  } 
  
  function newsletter_checker(){
  if (document.newsletter_form.full_name.value == "")
  {
    alert("Please enter your full name.")
    document.newsletter_form.full_name.focus()
    return false
  }
  if (!document.newsletter_form.email_address.value.match(/^[a-z0-9]+[_.a-z0-9-]+@[a-z0-9-]+\.+[a-z0-9.-]+$/i))
  {
    alert("Please enter a valid email address.");
    document.newsletter_form.email_address.focus();
    return false;
  }
    document.newsletter_form.submit()
  }