function removeAllOptions(select_box)
{
    var i;
    for(i=select_box.options.length-1;i>0;i--)
    {
      select_box.remove(i);
    }
}

function addOption(select_box,text,value,selected)
  {
  //  alert (text);
    var optn = document.createElement("OPTION");
    optn.text = text;
    optn.value = value;
    select_box.options.add(optn);
    if (selected) {
      optn.selected = true;
    }
  }
function update_dealer_models(what, model) {
  removeAllOptions(what.mod_F)
  var selected_manuf = what.man_F.value;
  //var v_man = what.maker_F.options[what.maker_F.selectedIndex].value;
  //addOption(what.mod_F, 'Model', '', true);
  for (x = 0; x < dealer_models.length; x++) {
	if (dealer_models[x][0].toLowerCase() == selected_manuf.toLowerCase()) {
	  if (dealer_models[x][1].toLowerCase() == model.toLowerCase()) selected = true;
	  else selected = false;
	  addOption(what.mod_F, dealer_models[x][1], dealer_models[x][1], selected);
	}
  }
}
function refine_dealer_results(from_mans) {
  document.refine_form.man_F.disabled = true;
  document.refine_form.mod_F.disabled = true;
  document.refine_form.maker_F.value = document.refine_form.man_F.value;
  if (from_mans == 'mans')
    document.refine_form.model_F.value = '';
  else
	document.refine_form.model_F.value = document.refine_form.mod_F.value;
  document.refine_form.submit();
}
function reset_dealer_results() {
  document.refine_form.man_F.disabled = true;
  document.refine_form.mod_F.disabled = true;
  document.refine_form.maker_F.value = '';
  document.refine_form.model_F.value = '';
  document.refine_form.submit();
}