1<html> 2<body bgcolor="white"> 3<script language="JavaScript"> 4function execXMLHttpRequest() 5{ 6 var url = document.getElementById("url").value; 7 var warningElement = document.getElementById("warning"); 8 if (url.indexOf(location.origin) != 0) { 9 warningElement.innerHTML = 10 'For cross-origin requests to succeed the server must return CORS headers:' + 11 '<pre>Access-Control-Allow-Origin: ' + location.origin + 12 '<br/>Access-Control-Allow-Header: My-Custom-Header</pre>'; 13 warningElement.style.display = 'block'; 14 } else { 15 warningElement.style.display = 'none'; 16 } 17 18 xhr = new XMLHttpRequest(); 19 xhr.open("GET", url, true); 20 xhr.setRequestHeader('My-Custom-Header', 'Some Value'); 21 xhr.onload = function(e) { 22 if (xhr.readyState === 4) { 23 var value = "Status Code: "+xhr.status; 24 if (xhr.status === 200) 25 value += "\n\n"+xhr.responseText; 26 document.getElementById('ta').value = value; 27 } 28 } 29 xhr.send(); 30} 31</script> 32<form> 33URL: <input type="text" id="url" value="http://tests/request"> 34<br/><input type="button" onclick="execXMLHttpRequest();" value="Execute XMLHttpRequest"> 35<br/><textarea rows="10" cols="40" id="ta"></textarea> 36</form> 37<div id="warning" style="display:none;font-weight:bold;"></div> 38</body> 39</html> 40