function checkFields()
  {
   missinginfo = "";
  
   if (document.myform.name.value == "")
       {
	 missinginfo += "\n-  Name";
       }

  if (document.myform.lastname.value == "")
       {
	 missinginfo += "\n-  Last Name";
       }

if (document.myform.email.value == "")
       {
	 missinginfo += "\n-  Email";
       }

   if (!document.myform.privacy.checked )
   {
	 missinginfo += "\n-  Privacy";
   }

   

   if (missinginfo != "")
       {
	  missinginfo ="Some compulsory fields have not been filled:\n" +
	  missinginfo + "\n\nPlease fill them and submit the form again";
	  alert(missinginfo);
	  return false;
       }
   else return true;
}