function verifynewsletter() {

if (document.newsletter.firstname.value == "") {
  alert('Please fill in your first name.')
  document.newsletter.firstname.focus() 
  return false } 

if (document.newsletter.lastname.value == "") {
  alert('Please fill in your last name.')
  document.newsletter.lastname.focus() 
  return false } 
  
if (document.newsletter.email.value == "")  {
   alert('Please fill in your email address.')
   document.newsletter.email.focus() 
   return false }
else {
if (!check_email(document.newsletter.email.value)) {
    alert('Email address is incorrect. Please enter your email again.')
    document.newsletter.email.focus()
    return false } 
 }
}