function SearchForFile(){
  var request_;
  var browser = navigator.appName;
  if(browser == "Microsoft Internet Explorer"){
    request_ = new ActiveXObject("Microsoft.XMLHTTP");
  }
  else
  {
    request_ = new XMLHttpRequest();
  }
  return request_;
}
var josh = SearchForFile();
function LoadPage(url){
    josh.open('GET', url, true); 
    josh.onreadystatechange = handleInfo;
    josh.send(null);
}
function handleInfo(){
    if(josh.readyState == 1){
    document.getElementById('PageViewing').innerHTML = '<br /><br /><br /><center><img src=loading3.gif></center>';
  }
    if(josh.readyState == 2){
    document.getElementById('PageViewing').innerHTML = '<br /><br /><br /><center><img src=loading3.gif></center>';
  }
    if(josh.readyState == 3){
    document.getElementById('PageViewing').innerHTML = '<br /><br /><br /><center><img src=loading3.gif></center>';
  }
  if(josh.readyState == 4){
    var response = josh.responseText;
    document.getElementById('PageViewing').innerHTML = response;
  }
}

<script type='text/javascript'>
function Form(){
	
	var ajaxRequest; 	
	try{
		ajaxRequest = new XMLHttpRequest();
	} catch (e){
		try{
			ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try{
				ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e){
				alert("Your browser does not support Ajax!");
				return false;
			}
		}
	}
	ajaxRequest.onreadystatechange = function(){
		if(ajaxRequest.readyState == 4){
			var ajaxDisplay = document.getElementById('result');
			ajaxDisplay.innerHTML = ajaxRequest.responseText;
		}
	}
var name = document.getElementById('name').value; 
var queryString = "?first=" + first; 
	document.getElementById('result').innerHTML="Loading...";
	ajaxRequest.open("GET", "_example.php" + queryString, true);
	ajaxRequest.send(null); 
}
</script>

<form>
NAME: <input type="text" id="name" name="name"><br />
<input type="button" onClick="Form()" value="Submit"><br />
</form>