function makeObject(){
var x; 
var browser = navigator.appName; 
if(browser == "Microsoft Internet Explorer"){
x = new ActiveXObject("Microsoft.XMLHTTP");
}else{
x = new XMLHttpRequest();
}
return x;
}

var request = makeObject();

var record=0;
tatalRecord=5
function chon(){
request.open('get', 'js/ajax.php?id=' + document.frmSearch.ddTown.value);
request.onreadystatechange = parseInfo; 
request.send('');
}
//function send data
function parseInfo(){
if(request.readyState == 1){
document.getElementById('quanhuyen').innerHTML = '<select id="title0" style="width:150px; " size="1"><option>Chon Quận / Huyện</option></select>';
}
if(request.readyState == 4){ 
var answer = request.responseText;
document.getElementById('quanhuyen').innerHTML = answer;
}
}