var dyn_carsOptionTree = [['80',[['Octavia','682']]],['93',[['Arteon','2623'],['Golf','812'],['ID.3','2744'],['ID.4','2768'],['ID.5','2841'],['ID.7','7322'],['Polo','819'],['T-Cross','2702'],['T-Roc','2661'],['Taigo','2812'],['Tayron','7658'],['Tiguan','1299'],['Tiguan Allspace','2733'],['Touareg','823']]]];
var dispmods = ["682","2623","812","2744","2768","2841","7322","819","2702","2661","2812","7658","1299","2733","823"];

function populateTarget(name,triggerObj,targetObj,emptyText) {

  eval ('tree = ' + name + 'OptionTree')

  triggerValue = getValue(triggerObj)
  
  for (i=0;i<tree.length;i++) {

    if (tree[i][0]==triggerValue) {
      break
    }

  }

  empty(targetObj)

  newOption = new Option()
  newOption.text = emptyText;

  newOption.value = ""
  targetObj.options[targetObj.options.length] = newOption

  if (i<tree.length) {

    options = tree[i][1]
    selectThisOption = 0

    for (i=0;i<options.length;i++) {

      newOption = new Option()
      newOption.text = options[i][0]
      newOption.value = options[i][1]
      targetObj.options[targetObj.options.length] = newOption

    }

    targetObj.options.length = options.length + 1;
  }

}

function empty(select) {

  select.options.length = 0

}

function getValue(formObj) {

  value = null

  if (formObj.options) { // select

    if (formObj.selectedIndex > -1)
      value = formObj.options[formObj.selectedIndex].value

  } else {

    if (formObj.length) { // radio
      for (var b = 0; b < formObj.length; b++)
        if (formObj[b].checked)
          value = formObj[b].value
    }
    else if (formObj.checked) // checkbox
      value = formObj.value

  }

  return value

}

function initSearch() {

  var id_extra = '';
  if (!document.getElementById) return false;
  if (!document.getElementById('make')) {
    if (!document.getElementById('make_id')) {
      return false;
    }
    else {
      id_extra = '_id';
    }
  }
  var makeSelect  = document.getElementById('make' + id_extra);

  // register change event
  makeSelect.onchange = function() {
    populateTarget('dyn_cars',this, document.getElementById('model' + id_extra), 'Model')
  }

  populateTarget('dyn_cars', makeSelect, document.getElementById('model' + id_extra), 'Model');
  
  var patt = /model_id=([0-9]+)/;
  if (patt.test(window.location.search)) {
    var selected_model = patt.exec(window.location.search);
    selected_model = selected_model[1];
    document.getElementById('model' + id_extra).value = selected_model;
  }

}

$(document).ready(function(){
  initSearch();
});