// Function to change map image
function changeMapImage(country_id)
{
  map_image = document.getElementById('country_map_image');
  if(map_image) map_image.src = country_map[country_id];
}

function clearList(list_name)
{
  search_list = document.getElementById('search_' + list_name);
  
  if(search_list)
  {
    len = search_list.options.length;
    
    for(i=len;i>0;i--)
      search_list.options[i-1] = null;
    
    if(search_list.size<=1)
    {
      search_list.options[0] = new Option("All", 0);
      search_list.selectedIndex = 0;
    }
  }
}

function filterCounties()
{
  // Clear counties and towns list
  clearList('counties');
  
  search_countries = document.getElementById('search_countries');
  search_counties = document.getElementById('search_counties');
  
  idx = search_countries.selectedIndex;
    
  if(idx>-1)
  {
    val = search_countries.options[idx].value;
    
    for(i=0;i<county_parent.length;i++)
    {
      if(county_parent[i]!=null)
      {
        if(county_parent[i]==val||val==0)
        {
          z = search_counties.options.length;
        
          search_counties.options[z] = new Option(county[i], county_value[i]);
        }
      }
    }
  }
  
  filterTowns();
}

function filterTowns()
{
  // Clear counties and towns list
  clearList('towns');
  
  search_countries = document.getElementById('search_countries');
  search_counties = document.getElementById('search_counties');
  search_towns = document.getElementById('search_towns');
  
  idx = search_counties.selectedIndex;
  
  idx2 = search_countries.selectedIndex;
  val2 = search_countries.options[idx2].value;
  
  if(idx>-1)
  {
    val = search_counties.options[idx].value;
    
    for(i=0;i<town_parent.length;i++)
    {
      if((val2==0&&idx==0)||town_parent[i]==val||(val==0&&townInCountry(town_value[i],val2)))
      {
        z = search_towns.options.length;
      
        search_towns.options[z] = new Option(town[i], town_value[i]);
      }
    }
  }
}

function townInCountry(town_id,country_id)
{
  town_idx = town_value.indexOf(town_id);
  
  county_id = town_parent[town_idx];
  
  county_idx = county_value.indexOf(county_id);
  
  country_val = county_parent[county_idx];
  
  if(country_val==country_id)
    return true;
  else
    return false;
}