function trainerForm() {
  
  var gender = (document.getElementById("fmTrainer_geschlecht_1").checked) ? 1 : 2;
  var size = document.getElementById("fmTrainer_groesse").selectedIndex;
  var sport = document.getElementById("fmTrainer_sport").selectedIndex;
  
  if (!size || !sport) {
    
    alert("Bitte füllen Sie alle Felder aus.");
    
    document.getElementById("trainer-human-img").innerHTML = '';
    document.getElementById("trainer-table").innerHTML = '';
    document.getElementById("trainer-plan-download").innerHTML = '';
    
    return false;
    
  }
  
  var genderName = (gender == 1) ? "woman" : "man";
  
  document.getElementById("trainer-human-img").innerHTML = '<img src="./fileadmin/img/trainer/' + genderName + '-' + size + '.jpg" alt="" />';
  
  document.getElementById("trainer-table").innerHTML = '<b>Ihr persönlicher Tagesbedarf</b><br /><img src="./fileadmin/img/trainer/table-' + gender + '-' + size + '-' + sport + '.jpg" alt="" />';
  
  document.getElementById("trainer-plan-download").innerHTML = '<img src="./fileadmin/img/icon-link.gif" alt="" /> <a href="./fileadmin/pdf/trainer/' + gender + '-' + size + '-' + sport + '.pdf" target="_blank">Ihr persönlicher Ernährungsplan als Download</a>';
  
  return false;
  
}

function updateTrainerFormSelect(genderId) {
  
  var genderSize = [
      // Frau
      [
          "Bitte auswählen",
          "155 – 169",
          "170 – 182"
          ],
      // Mann
      [
          "Bitte auswählen",
          "160 – 174",
          "175 – 187"
          ]
      ];
  
  for (var i = 0; i < genderSize[0].length; i++)
    document.getElementById("fmTrainer_groesse").options[i].text = genderSize[genderId - 1][i];
  
  with (document.getElementById("fmTrainer_sport").options[2]) {
    
    if (genderId == 1)
      text = "3 Stunden";
    else
      text = "4 Stunden";
    
  }
  
  return;
  
}