<form action="#">
            <p><label>Номер АЗС:</label> <input id="number" type="text" autocomplete="off"></p>
            <p><label>Регион:</label> <input id="region" type="text" autocomplete="off"></p>
            <p><label>Город:</label> <input id="city" type="text" autocomplete="off"></p>
            <p><label>Улица:</label> <input id="street" type="text" autocomplete="off"></p>
        </form>

$(function(){

$('#number').autocomplete('data.php?mode=number', {
    width: 200,
    max: 20
});


$('#region').autocomplete('data.php?mode=region', {
    width: 200,
    max: 20
});

$('#city').autocomplete('data.php?mode=city', {
    width: 200,
    max: 20
});

    $('#street').autocomplete('data.php?mode=street', {
    width: 200,
    max: 20
});});

switch ($_GET['mode']) {
case 'number': 
    $sRequest = "SELECT DISTINCT `number_azs` FROM `address` WHERE `number_azs` LIKE '%{$sParam}%'";
    $aItemInfo = $GLOBALS['MySQL']->getAll($sRequest);
    foreach ($aItemInfo as $aValues) {
        echo $aValues['number_azs'] . "\n";
    }
    break;
case 'region': 
    $sRequest = "SELECT DISTINCT `region_azs` FROM `address` WHERE `region_azs` LIKE '%{$sParam}%'";
    $aItemInfo = $GLOBALS['MySQL']->getAll($sRequest);
    foreach ($aItemInfo as $aValues) {
        echo $aValues['region_azs'] . "\n";
                }
    break;
        case 'city': 
    $sRequest = "SELECT DISTINCT `city_azs` FROM `address` WHERE `city_azs` LIKE '%{$sParam}%'";
    $aItemInfo = $GLOBALS['MySQL']->getAll($sRequest);
    foreach ($aItemInfo as $aValues) {
        echo $aValues['city_azs'] . "\n";
                }
    break;
        case 'street': // Используем базу данных как источник данных
    $sRequest = "SELECT DISTINCT `street_azs` FROM `address` WHERE `street_azs` LIKE '%{$sParam}%'";
    $aItemInfo = $GLOBALS['MySQL']->getAll($sRequest);
    foreach ($aItemInfo as $aValues) {
        echo $aValues['street_azs'] . "\n";
                }
    break;}