Basic AJAX connection using the POST method to retrieve content

Hello guys,

I have been working on a project for school which used AJAX and I just wanted you guys to have this code for reference. This code basically makes a call to a PHP script which gets Zip Code information (city and state) and then adds them into your web page. I used a span tag with id of ???zipinfo??? to act as a holder for the content that was going to be retrieved. Hopefully this helps some of you in your projects.

//Get Zip Code Information

function zipInfo(zipcode) {

fieldValue = ???connection=zipInfo&zip=???+zipcode;

var url=???includes/management.php???;

httpRequest(???POST???, url, true, fieldValue, function(result){

document.getElementById(???zipInfo???).innerHTML = result;



//AJAX Request

function httpRequest(reqType, url, asynch, fieldValue, callback) {

request = new XMLHttpRequest();,url,asynch);

request.setRequestHeader(???Content-type???, ???application/x-www-form-urlencoded???);

request.setRequestHeader(???Content-length???, fieldValue.length);

request.setRequestHeader(???Connection???, ???close???);


request.onreadystatechange = function() {//Call a function when the state changes.

if(request.readyState == 4 && request.status == 200) {






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