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)
  {
    var optn = document.createElement("OPTION");
    optn.text = text;
    optn.value = value;
    select_box.options.add(optn);
  }

  var select_box;
  var current_model;

  function populate_select()
  {
    var myajax=ajaxpack.ajaxobj;
    var selected;

    if (myajax.readyState == 4){ //if request of file completed
      if (myajax.status==200 || window.location.href.indexOf("http")==-1){
        models = myajax.responseText.split("\n");

        for (var i=0, len=models.length; i<len; ++i){
          if (models[i] == '')
          {
            continue;
          }

          addOption(select_box, models[i], models[i]);

          if (current_model == models[i-1]) {
            select_box.options[i].selected = true;
          }
        }
        if (select_box.options[0].text == "Loading...") {
        	select_box.options[0].text = "Any";
        }
      }
    }
  }

  function update_models_cf(model_F)
  {
    select_box = document.carfinder_form.model_F;
    removeAllOptions(select_box);
    current_model = model_F;
    if (!current_model) {
      current_model = 0;
      select_box.options[0] = new Option( 'Loading...', '' );
    }
    ajaxpack.getAjaxRequest('/ajax-models-list.php', 'maker_F='+document.carfinder_form.maker_F.value, populate_select, 'txt');
  }

function validate_carfinder_form() {
	var valid = true;
	var msg = '';
	var min_price = parseInt(document.carfinder_form.from_price_F.value);
	var max_price = parseInt(document.carfinder_form.to_price_F.value);
	if (document.carfinder_form.maker_F.value == '' || document.carfinder_form.maker_F.value == 0) {
		msg = 'Please choose a manufacturer\n';
		valid = false;
	}
	if (document.carfinder_form.model_F.value == '' || document.carfinder_form.model_F.value == 'Any') {
		msg += 'Please choose a model\n';
		valid = false;
	}
	if (document.carfinder_form.email_F.value == '' || document.carfinder_form.email_F.value == 'Enter email address here...') {
		msg += 'Please, enter your email address\n';
		valid = false;
	} else if (!validate_email(document.carfinder_form.email_F.value)) {
		msg += 'Please, enter a valid email address\n';
		valid = false;
	}
	if (document.carfinder_form.postcode_F.value == '' || document.carfinder_form.postcode_F.value == 'Enter Postcode...') {
		msg += 'Please, enter your Postcode\n';
		valid = false;
	}
	if (min_price > max_price){
	  msg = msg + "Please, choose correct minimum and maximum prices.\n";
	  msg = msg + "Minimum price can not be larger than Maximum price.\n";
	  valid = false;
	}	
	if (!valid) alert(msg);
	return valid;
}