/**
 * check_select is for control if selected item has value 
 * created by Ondrej Letacek <Ondrej@nestdesign.com> 
 **/
 
function fillList( box, arr, defaultValue) {
  DselectedIndex = 0;
  for (key in arr) {
    option = new Option( arr[key],key);
    if(key == defaultValue){
      DselectedIndex = box.length;
    }
    box.options[box.length] = option;
  }
  box.selectedIndex=DselectedIndex;
}
function emptyList( box ) {
  if(box!=null){
    while ( box.options.length ) box.options[0] = null;
  }
}
function changeSubcategories(submenu,topmenu){
  if(submenu){
    emptyList(submenu);
    if(my_subcategories[topmenu[topmenu.selectedIndex].value] && my_subcategories[topmenu[topmenu.selectedIndex].value].length > 0){
      option = new Option( 'All',0);
      submenu.options[submenu.length] = option;
      fillList(submenu,my_subcategories[topmenu[topmenu.selectedIndex].value],0);
      submenu.style.display = 'inline';
    }else{
      submenu.style.display = 'none';
    }
  }
}

function changeSubcategories2(submenu,topmenu,firstitem){
  if(submenu){
    emptyList(submenu);
    if(my_subcategories[topmenu[topmenu.selectedIndex].value] && my_subcategories[topmenu[topmenu.selectedIndex].value].length > 0){
      option = new Option( '-- SELECT --',0);
      submenu.options[submenu.length] = option;
      fillList(submenu,my_subcategories[topmenu[topmenu.selectedIndex].value],0);
      submenu.style.display = 'inline';
    }else{
      submenu.style.display = 'none';
    }
  }
}
// example or running:
// onchange="changeAnyArray(document.getElementById('town_id'),this,my_towns,0,'-- Select town --'
function changeAnyArray(submenu,topmenu,my_array,hide_empty,default_item){
  if(submenu){
    emptyList(submenu);
    if(default_item){
      option = new Option(default_item,0);
      submenu.options[submenu.length] = option;
    }
    if(my_array[topmenu[topmenu.selectedIndex].value] && my_array[topmenu[topmenu.selectedIndex].value].length > 0){
      fillList(submenu,my_array[topmenu[topmenu.selectedIndex].value],0);
    }
    if(hide_empty){
      if(my_array[topmenu[topmenu.selectedIndex].value] && my_array[topmenu[topmenu.selectedIndex].value].length > 0){
        submenu.style.display = 'inline';
      }else{
        submenu.style.display = 'none';
      }
    }
  }
}