[ruslan_mart]

var XMLRequest;

(function() {
	var req, reqTimeout,
		_XMLRequest = XMLHttpRequest || window.ActiveXObject && function() {
			return new ActiveXObject('Msxml2.XMLHTTP');
		}
	XMLRequest = function(action, data, callback, onError) {
		var i, keys = [];
		if(req) {
			clearTimeout(reqTimeout);
			req.abort();
			req = null;
		}
		req = new _XMLRequest();
		req.open('POST', action, true);
		req.onreadystatechange = function() {
			if(req.readyState != 4) return;
			clearTimeout(reqTimeout);
			var reqTmp = req;
			req = null;
			if(reqTmp.status == 200) callback(reqTmp.responseText);
			else if(onError) onError(reqTmp.statusText);
		};
		req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		for(i in data) keys.push(i + '=' + encodeURIComponent(data[i]));
		req.send(keys.join('&') || null);
		reqTimeout = setTimeout(function() {
			req.abort();
			req = null;
			if(onError) onError('Timeout');
		}, 3E4);
	}
})();

XMLRequest('server.php', {foo: true}, function(data) {
     document.getElementById('ajax').innerHTML = data;
});