function checkEM() {
  var myem = document.form.CR_Email.value;
  var url = "checkEM.php";
  url = url + "?myAddr="+myem+"&dummy=" + new Date().getTime();
  request.open("GET", url, true);
  request.onreadystatechange = updatePage;
  request.send(null);
}

function updatePage() {
  if (request.readyState == 4) {
    if (request.status == 200) {
      // if valid, nothing happens, if not, set message
	  var exists = request.responseText;
	  var emMsgDiv = document.getElementById("emMsg");
	  if (exists == 'TRUE') {  
    	  replaceText(emMsgDiv, 'The email address you entered is already in our system. Please use the login box to the right to continue to edit your listing.');
		  emMsgDiv.style.display = 'block';
		} else {
		  emMsgDiv.style.display = 'none';
		}
    } else {
      var message = request.getResponseHeader("Status");
      if ((message.length == null) || (message.length <= 0)) {
        alert("Error! Request status is " + request.status);
      } else {
        alert(message);
      }
    }
  }
}