function getXmlHttpObject(){
   if (window.XMLHttpRequest)
      return new XMLHttpRequest();
   else if (window.ActiveXObject)
      return new ActiveXObject("Microsoft.XMLHTTP");
   else {
      alert("Obiekt XMLHttpRequest nie jest obsugiwany!");
      return null;
   }
}

function handleHttpResponse() {
   if (http.readyState == 4) {
      results = http.responseText;
      alert(results);
   }
}

function doSomeStuff() {
   var post_arg1 = document.my_form.post_arg1.value;
   var post_arg2 = document.my_form.post_arg2.value;
   var post_url = 'http://yahoo.com/form_do'
      post_data = 'post_arg1=' + post_arg1 + '&post_arg2=' + post_arg2;
   http.open("POST", post_url);
   http.setRequestHeader('Content-Type', 
      'application/x-www-form-urlencoded; charset=iso-8859-2');
   http.send(post_data);
   http.onreadystatechange = handleHttpResponse;
   return false;
}

var http = getXmlHttpObject();
