var factHandle = createRequestObject();

function createRequestObject()
{
  var reqObj ;
  var browser = navigator.appName;
  if(browser == 'Microsoft Internet Explorer') {
    reqObj = new ActiveXObject("Microsoft.XMLHTTP");
  } else {
    reqObj = new XMLHttpRequest();
  }
  return reqObj;
}

function sndReq(action) {
	factHandle.open('get', '/hedgehogs/didyouknow.php');
	factHandle.onreadystatechange = handleResponse;
	factHandle.send(null);
}

function handleResponse() {
	if(factHandle.readyState == 4) {
		var response = factHandle.responseText;
		document.getElementById('randomfact').innerHTML = response;
	}
}

clearInterval();
var myInterval = setInterval("sndReq()", 20000);