Need help with some ajax code

function Ajax() {
	knackerEvent(e);
	document.getElementById('AJAX_RESULT').innerHTML = '<div align="center"><img src="../images/loader.gif" width="32" height="32" /><br />Searching. . .</div>';
	
	http = GetXmlHttpObject();
	alert("Created XML Request Object.");

 	http.open("POST", "search.php", true);
	alert("Opened a Page With The POST Method.");
	
  	http.onreadystatechange = stateChanged;
	http.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");  	
	
	http.send("q=" + document.getElementById('AJAX_FORM').elements['q'].value);
	alert('Sent Post Data.');
}

function stateChanged()  { 
  if (http.readyState == 4 || http.readyState == "complete") { 
    if (http.status == 200) {
		document.getElementById("AJAX_RESULT").innerHTML = http.responseText 
	} else {
		document.getElementById('AJAX_RESULT').innerHTML = '<div align="center"><img src="../images/error.png" width="37" height="37" /><br /><span class="error">An error occured.</span></div>';
	}
  } else {
	document.getElementById('AJAX_RESULT').innerHTML = '<div align="center"><img src="../images/error.png" width="37" height="37" /><br /><span class="error">An error occured.</span></div>'; 
  }
}

function GetXmlHttpObject() { 
	var objXMLHttp = null
	if (window.XMLHttpRequest) { objXMLHttp = new XMLHttpRequest() } 
	else if (window.ActiveXObject) { objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP") }
	return objXMLHttp
}