<tr valign="top">
<td class="empty"></td>
<td class="label" nowrap colspan="2" width="20%"><span class="lblrequired"><br><label for="id35216826">Страна:</label></span></td>
<td class="empty"><br><select name=country onclick="requestdata('?count='+ country.value);">
 <option> Russia</option>
 <option> США</option>
 <option> Германия</option>
</select></td>
</tr>
<tr valign="top">
<td class="empty"></td>
<td class="label" nowrap colspan="2" width="20%"><span class="lblrequired"><label for="id35216826">Город:</label></span></td>
<td class="empty">
<div id=towns></id>
</td>
</tr>

<script>
var req;
var reqTimeout;
 
function loadXMLDoc(url) {
    req = null;
    if (window.XMLHttpRequest) {
        try {
            req = new XMLHttpRequest();
        } catch (e){}
    } else if (window.ActiveXObject) {
        try {
            req = new ActiveXObject('Msxml2.XMLHTTP');
        } catch (e){
            try {
                req = new ActiveXObject('Microsoft.XMLHTTP');
            } catch (e){}
        }
    }
 
    if (req) {
        req.onreadystatechange = processReqChange;
        req.open("GET", url, true);
        req.send(null);
        reqTimeout = setTimeout("req.abort();",  5000 );
    } else {
        alert("Браузер не поддерживает AJAX");
    }
}
 
function processReqChange() {

 
    if (req.readyState ==  4 ) {
        clearTimeout(reqTimeout);
 
 
        // only if "OK"  response
        if (req.status ==  200 ) {
           
		   document.getElementById('towns').innerHTML = req.responseText;
	
        } else {
           document.getElementById('towns').innerHTML = req.responseText;
        }
    }  
}
 

 
function requestdata(params)
{
  loadXMLDoc('town.php'+params);
}
</script>

<?php
header("Content-type: text/plain; charset=windows1251");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
 include("functions.php");
 
 $country = $_GET['count'];

 
 if ($country == "Russia" ) {
 
 
 echo "
<select name=town>
 <option> Москва</option>
 <option> Питер</option>
 <option> Ванино</option>
</select>
 ";
 }else {
  echo "
незнаю
 ";
 }
 
?>