function reset_image () {
  var xmlhttp = false;
  /*@cc_on @*/
  /*@if (@_jscript_version >= 5)
  // JScript gives us Conditional compilation, we can cope with old IE versions.
  // and security blocked creation of the objects.
    try {
      xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
      try {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (E) {
        xmlhttp = false;
      }
    }
  @end @*/
  if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
    try {
      xmlhttp = new XMLHttpRequest();
    } catch (e) {
      xmlhttp = false;
    }
  }
  if (!xmlhttp && window.createRequest) {
    try {
      xmlhttp = window.createRequest();
    } catch (e) {
      xmlhttp = false;
    }
  }

  if (xmlhttp) {
    xmlhttp.open("GET", "/rotation_image.php", false);
    xmlhttp.send(null);
    var new_img = xmlhttp.responseText;

    if (document.getElementById("rotation_image").src != new_img) {
      document.getElementById("rotation_image").src = new_img;
    }
  }
}

setInterval("reset_image()", 5000);