<?php
$db = mysql_connect ("localhost", "root", "");
mysql_query ("set character_set_client='cp1251'");
mysql_query ("set character_set_results='cp1251'");
mysql_query ("set collation_connection='cp1251_general_ci'");
mysql_select_db("cars",$db);
 ?>
 
<script src="JsHttpRequest.js"></script>
 
<!-- Здесь мы подключили библиотеку. А теперь пишем функцию, которую назовем doload() -->
 
<script>
function doload(value){
var req=new JsHttpRequest();
req.onreadystatechange=function(){
if(req.readyState==4) document.getElementById("result").innerHTML=req.responseText;}
req.open(null,"select2.php",true);
req.send({country:value});}
</script>
 
<form action="sript.php" method="POST">
 
<select name="country" onchange="doload(this.value);">
<option value="">--Выберите марку--
<?php
$sql = mysql_query ("SELECT DISTINCT brand FROM t1");
while ($new_brand = mysql_fetch_array($sql))
        echo "<option value=".'"'.$new_brand['brand'].'"'.">".$new_brand['brand']."";
?>
</select>
 
<br><br>
 
<div id="result"></div>
 
<br><br>
 
<input type="submit" value="Отправить">
 
</form>

<?php
$db = mysql_connect ("localhost", "root", "");
mysql_select_db("cars",$db);
 
require("JsHttpRequest.php");
$JsHttpRequest=new JsHttpRequest("windows-1251");
 
switch($_REQUEST["country"]):
 
case "Mitsubishi":
$html="<select name=\"provider\" id=\"provider\">
<option value="no_action">--Выберите модель--
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = 'Mitsubishi'");    
while ($new_model= mysql_fetch_array($sql))
    echo "<option value=".'"'.$new_model['model'].'"'.">".$new_model['model']."";
</select>";
break;
 
case "Suzuki":
$html="<select name=\"provider\" id=\"provider\">
<option value="no_action">--Выберите модель--
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = 'Suzuki'");    
while ($new_model = mysql_fetch_array($sql))
    echo "<option value=".'"'.$new_model['model'].'"'.">".$new_model['model']."";
</select>";
break;
 
case "Hyundai":
$html="<select name=\"provider\" id=\"provider\">
<option value="no_action">--Выберите модель--
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = 'Hyundai'");  
while ($new_model = mysql_fetch_array($sql))
    echo "<option value=".'"'.$new_model['model'].'"'.">".$new_model['model']."";
</select>";
break;
 
default: $html=null;
endswitch;
 
echo $html;
?>

<?php
$db = mysql_connect ("localhost", "root", "");
mysql_query ("set character_set_client='cp1251'");
mysql_query ("set character_set_results='cp1251'");
mysql_query ("set collation_connection='cp1251_general_ci'");
mysql_select_db("cars",$db);
 
require("JsHttpRequest.php");
$JsHttpRequest=new JsHttpRequest("windows-1251");
?>
<select name=\"model\" id=\"model\">
<option value="no_action">--Выберите модель--</option>
<?
if($_REQUEST["brand"] == "Mitsubishi"){
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = 'Mitsubishi'");
while ($new_model= mysql_fetch_array($sql))
    echo '<option value='.$new_model['model'].'>'.$new_model['model'].'</option>';
} else {echo 'Error!';}
if($_REQUEST["brand"] == "Suzuki"){
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = 'Suzuki'");
while ($new_model= mysql_fetch_array($sql))
    echo '<option value='.$new_model['model'].'>'.$new_model['model'].'</option>';
} else {echo 'Error!';}
if($_REQUEST["brand"] == "Hyundai"){
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = 'Hyundai'");
while ($new_model= mysql_fetch_array($sql))
    echo '<option value='.$new_model['model'].'>'.$new_model['model'].'</option>';
} else {echo 'Error!';}
?>
</select>

if($_REQUEST["brand"] == true){
$sql = mysql_query ("SELECT DISTINCT model FROM t1 WHERE brand = ".$_REQUEST["brand"]."");
while ($new_model= mysql_fetch_array($sql))
    echo '<option value='.$new_model['model'].'>'.$new_model['model'].'</option>';
} else {echo 'Error!';}

 
$sql = mysql_query ('SELECT DISTINCT model FROM t1 WHERE brand = "'.mysql_real_escape_string($_REQUEST["brand"]).'"');
if($sql) {
    while ($new_model= mysql_fetch_array($sql)) {
        echo '<option value="'.$new_model['model'].'">'.$new_model['model'].'</option>';
    }
} else {
    echo mysql_error();
}