function chkNewsletter()
{
   if(document.newsletter.name.value == "")
   {
      alert("Please fill in your name");
      document.newsletter.name.focus();
      return false;  
   }
   
   if(document.newsletter.email.value == "")
   {
      alert("Please fill in your email address");
      document.newsletter.email.focus();
      return false;  
   }
   
   if(
        document.newsletter.email.value.indexOf("@") == -1 || 
        document.newsletter.email.value.indexOf(".") == -1 || 
        document.newsletter.email.value.length < 6
     )
   {
      alert("Not a valid email address");
      document.newsletter.email.focus();
      return false;  
   }
}

function chkNewsletterUnsubscribe()
{
   if(document.newsletter.email.value == "")
   {
      alert("Please fill in your email address");
      document.newsletter.email.focus();
      return false;  
   }
   
   if(
        document.newsletter.email.value.indexOf("@") == -1 || 
        document.newsletter.email.value.indexOf(".") == -1 || 
        document.newsletter.email.value.length < 6
     )
   {
      alert("Not a valid email address");
      document.newsletter.email.focus();
      return false;  
   }
}