180. varhttpRequest;if (window.XMLHttpRequest) { // Mozilla, Safari, ... httpRequest = new XMLHttpRequest(); } else if (window.ActiveXObject) { // IE httpRequest= new ActiveXObject("Microsoft.XMLHTTP"); }httpRequest.onreadystatechange = function(){ if (httpRequest.readyState === 4) { if (httpRequest.status === 200) { // perfect! } else { // there was a problem with the request, // for example the response may be a 404 (Not Found) // or 500 (Internal Server Error) response codes} } else { // still not ready }};httpRequest.open('GET', ‘http://url', true);httpRequest.send(null); 5/7/2011 51