function CheckContactForm(){
  if (document.ContactForm.Name.value==""){
    alert("Please enter your name.");
    return false;
  }
  else if(document.ContactForm.Email.value==""){
   alert("Please enter your email address.")
   return false;
  }
  else if(document.ContactForm.Subject.value == ""){
    alert("You must enter a subject.");
    return false;
  }
  else if(document.ContactForm.Message.value==""){
   alert("Please enter your message.")
   return false;
  }
  else{
   return true;
  }
}