function checkFormUnit(form)
  {

    if(form.merchant.value == '') {
      alert("Error: Please select a merchant!");
      form.merchant.focus();
      return false;
    }

    if(form.afid.value == '') {
      alert("Error: Please enter your affiliate ID!");
      form.afid.focus();
      return false;
    }
    return true;
  }

    function checkFormProductUnit(form)
  {

    if(form.afid.value == '') {
      alert("Error: Please enter your affiliate ID!");
      form.afid.focus();
      return false;
    }
    return true;
  }