foodstore.js

var xmlHttp = createXmlHttpRequestObject();

function createXmlHttpRequestObject() {
	var xmlHttp;

	if(window.ActiveXObject) {
		try {
			xmlHttp = new ActiveXObject ("Microsoft.XMLHTTP");
		}catch(e) {
			xmlHttp = false;
		}
	}else{
		try {
			xmlHttp = new XMLHttpRequest();
		}catch(e){
			xmlHttp = false;
		}
	}

	if(!xmlHttp)
		alert("cant create that object hoss!");
	else
		return xmlHttp;
}

function process() {
	if (xmlHttp.readyState==0 || xmlHttp.readyState==4) {
		food = encodeURIComponent(document.getElementById("userInput").value);
		xmlHttp.open("GET", "foodstore.php?food=" + food, true);
		xmlHttp.onreadystatechange = handleServerResponse;
		xmlHttp.send(null);
	}else{
			setTimeout('process()',1000);
	}
}

function handleServerResponse() {
	if(xmlHttp.readyState==4) {
		if(xmlHttp.status==200){
			xmlResponse = xmlHttp.responseXML;
			xmlDocumentElement = xmlResponse.documentElement;
			message = xmlDocumentElement.firstChild.data;
			document.getElementById("underInput").innerHTML = '<span style="color:blue">' + message + '</span>';
			setTimeout('process()',1000);
		}else{
			alert('something went wrong!');
		}
	}
}