function spacer(x){
  if (x == "subject_checker"){
    if (document.contact.subject_option.value == "") {
      alert("Please select a correct option.");
    }
  }
}

function submit_form() {
  if (document.contact.first_name.value         == "" ||
      document.contact.last_name.value          == "" ||
      document.contact.email.value              == "" ||
      document.contact.email.value.indexOf("@") == -1 ||
      document.contact.email.value.indexOf(".") == -1 ||
      document.contact.subject_option.value     == "" ||
      document.contact.message.value            == ""){
    alert("Please answer required fields.");
  } else {
    document.contact.submit();
  }
}