store.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("Can't 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", "store.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>';

		}else{
			alert('Something went wrong!');
	}
}