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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<!-- saved from url=(0014)about:internet -->
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-2">
  <title> ITU ajax </title>

  <style type="text/css">
  div, input { margin: 10px; }
  </style>
</head>
<body>

<div id="chatArea" style="height: 300px; border: solid #aaa 1px; overflow:auto;"></div>

<form onsubmit="return uploadData()">
  <input type="text" id="newMessageString">
  <input type="submit" value="send">
</form>

<div id="status" style="border: solid #aaa 1px; ">&nbsp;</div>


<script type="text/javascript">


/***
  * XMLHttpRequest object constructor (for compatibility with various browsers)
  */

function createXmlHttpRequestObject() {
    var xmlHttp;
  try {
    xmlHttp = new XMLHttpRequest(); //should work on all browsers except IE6 or older
  } catch (e) {
    try {
      xmlHttp = new ActiveXObject("Microsoft.XMLHttp"); //browser is IE6 or older
    } catch (e) {
      // ignore error
    }
  }
  if (!xmlHttp) {
    alert ("Error creating the XMLHttpRequest object.");
  } else {
    return xmlHttp;
  }
}

function uploadData() {
  document.getElementById("status").innerHTML = "uploadData()";

    var message = document.getElementById("newMessageString").value;

  try {
    var xmlHttp = createXmlHttpRequestObject();//stores XMLHttpRequestObject

    var params = "data=" + message;
    xmlHttp.open("POST", "http://www.stud.fit.vutbr.cz/~xmlich02/itu-ajax/api.php" , true);
	xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;");
	xmlHttp.onreadystatechange = downloadData;
	xmlHttp.send(params);

  } catch (e) {
    alert(e.toString());
  }

    document.getElementById("newMessageString").value = "";

  return false; // to avoid default form submit behavior
}

function downloadData() {
  document.getElementById("status").innerHTML = "downloadData()";
    var last_id = 0;
    var xmlHttp = createXmlHttpRequestObject();
    xmlHttp.open("GET", "http://www.stud.fit.vutbr.cz/~xmlich02/itu-ajax/api.php", true);
    xmlHttp.onreadystatechange = mojeFunkceProZpracovaniPozadavku;

    function mojeFunkceProZpracovaniPozadavku() {
        if ((xmlHttp.readyState == 4) && (xmlHttp.status == 200)) { //process is completed and http status is OK
            var bar = document.getElementById("chatArea");
            var pole = JSON.parse(xmlHttp.responseText);
            var start = false;
            for (var i in pole) {
                if (pole[i].id > last_id) {
                    last_id = pole[i].id;
                    bar.innerHTML += "<b>" + pole[i].login + "</b>: " + pole[i].cnt + '<br>';
                }
            }
        }
    };
    xmlHttp.send(null);

}
//// put your code here

downloadData();
setInterval(downloadData, 3000);
</script>

</body></html>