title: differences of these two type of ajax syntax and use
body: <p>When I first met Ajax, this snytax is always in my eye sight :</p>
  
  <pre><code>&lt;script&gt;
  function loadXMLDoc()
  {
  var xmlhttp;
  if (window.XMLHttpRequest)
    {// code for IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp=new XMLHttpRequest();
    }
  else
    {// code for IE6, IE5
    xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
  xmlhttp.onreadystatechange=function()
    {
    if (xmlhttp.readyState==4 &amp;&amp; xmlhttp.status==200)
      {
      document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
      }
    }
  xmlhttp.open("GET","ajax_info.txt",true);
  xmlhttp.send();
  }
  &lt;/script&gt;
  </code></pre>
  
  <p>But today I come across with this :</p>
  
  <p>I think this one is more flexible? I can work with jquery.. but why it did not require XMLHttpRequest like above?</p>
  
  <pre><code>$(function){
   $('#something').change(function(){
     $.ajax({
        type: 'GET',
        url: 'something.php',
        data: 'ip=' + $(something).val(),
        success: function(msg) {
        $('#result').html(msg);
        }
  });
  }
  };
  </code></pre>