function checkCommercial()
{
  
  //alert(document.getElementById('commercial_enquiry_type_purchase_id').checked);
  // PURCHASE OR REMORTGAGES
  if ( document.getElementById('commercial_enquiry_type_purchase_id').checked == false && document.getElementById('commercial_enquiry_type_remortgage_id').checked == false) {
    alert('Please select Purchase or Remortgage.');
    (document.getElementById('commercial_enquiry_type_purchase_id')).focus();
    return false;
  }

  // AMOUNT
  if ( document.getElementById('commercial_amount_required_id').value == '' ) {
    alert('Please enter required amount .');
    (document.getElementById('commercial_amount_required_id')).focus();
    return false;
  }

  // TYPE OF PROPERTY
  if (document.getElementById('commercial_type_of_property_id').options[document.getElementById('commercial_type_of_property_id').selectedIndex].value == "") {
    alert('Please chosse type of property.');
    (document.getElementById('commercial_type_of_property_id')).focus();
    return false;
  }


  // FREEHOLD OR LEASEHOLD
  if ( document.getElementById('commercial_property_hold_leashold_id').checked == false && document.getElementById('commercial_property_hold_freehold_id').checked == false) {
    alert('Please select Freehold or Leasehold.');
    (document.getElementById('commercial_property_hold_freehold_id')).focus();
    return false;
  }


  // APP 1 first name
  if ( document.getElementById('commercial_applicant_one_firstname_id').value == '' ) {
    alert('Please enter Applicant One First Name.');
    (document.getElementById('commercial_applicant_one_firstname_id')).focus();
    return false;
  }

  // APP 1 Surname name
  if ( document.getElementById('commercial_applicant_one_surname_id').value == '' ) {
    alert('Please enter Applicant One Surname.');
    (document.getElementById('commercial_applicant_one_surname_id')).focus();
    return false;
  }

  
  // ---- APP 2 ---
  if (document.getElementById('commercial_applicants_count_id').options[document.getElementById('commercial_applicants_count_id').selectedIndex].value == "2")
  {
    // APP 2 first name
    if ( document.getElementById('commercial_applicant_two_firstname_id').value == '' ) {
      alert('Please enter Applicant Two First Name.');
      (document.getElementById('commercial_applicant_two_firstname_id')).focus();
      return false;
    }

    // APP 1 Surname name
    if ( document.getElementById('commercial_applicant_two_surname_id').value == '' ) {
      alert('Please enter Applicant Two Surname.');
      (document.getElementById('commercial_applicant_two_surname_id')).focus();
      return false;
    }
  } // APP 2


  // ADDRESS
  if ( document.getElementById('commercial_address_id').value == '' ) {
    alert('Please enter Your Address.');
    (document.getElementById('commercial_address_id')).focus();
    return false;
  }

  // POSTCODE
  if ( document.getElementById('commercial_postcode_id').value == '' ) {
    alert('Please enter Your Postcode.');
    (document.getElementById('commercial_postcode_id')).focus();
    return false;
  }



  // EMAIL
  if ( !checkEmail( document.getElementById('commercial_email_id').value)) {
    alert('Please fill your Email correctly.');
    (document.getElementById('commercial_email_id')).focus();
    return false;
  }
                                                                                                  
  if ( document.getElementById('commercial_telephone_id').value == '' && document.getElementById('commercial_mobile_id').value == '' ) {
    alert('Please enter at least one telephone contact.');
    (document.getElementById('commercial_telephone_id')).focus();
    return false;
  }

  return true;
}


// function checks correct of email
function checkEmail(adresa){
   var pozice_zavinace = adresa.indexOf("@");
   var pozice_tecky = adresa.indexOf(".");
    if (pozice_zavinace < 0)
        return false;
    if (pozice_tecky < 0)
        return false;
    var cast_pred_zavinacem = adresa.substring(0,pozice_zavinace);
    var cast_po_zavinaci = adresa.substring(pozice_zavinace+1,adresa.length);
    if (cast_po_zavinaci.indexOf("@") >= 0)
        return false;
    if (cast_pred_zavinacem.length <= 0)
        return false;
    if (cast_po_zavinaci.length <= 0)
        return false;

    // ... pr(ípadné další kontroly ...

    return true;
}