var imageXmlRequest = null;
function loadImageXMLHttpRequest(){
	imageXmlRequest = null;
	if(window.XMLHttpRequest){
		imageXmlRequest = new XMLHttpRequest();
	}else if(window.ActiveXObject){
		try{
			imageXmlRequest = new ActiveXObject("Msxml2.XMLHTTP");
		}catch(e){
			try{
				imageXmlRequest = new ActiveXObject("Microsoft.XMLHTTP");
			}catch(e){
				alert("Faile to create xmlhttprequest instance");
			}
		}
	}
}
function doImageRequest(url){
	loadImageXMLHttpRequest();
	   imageXmlRequest.onreadystatechange=processImageRequest;
	try{
		imageXmlRequest.open("POST",url,true);
	}catch(e){
		alert("Problem Communicating with Server\n"+e);
	}
	imageXmlRequest.send(null);
}

function processImageRequest(){
	if(imageXmlRequest.readyState == 4){
		if(imageXmlRequest.status == 200 ){
			document.images.image.src=imageXmlRequest.responseText;
		}else{
			alert("Problem with server response:\n " + imageXmlRequest.statusText);
	}
  }
}

function changeImageCode(){
 var url = "changeImage";
 doImageRequest(url);
}