Any reason mine is not working? I broke my head!

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function () {
  if(xhr.readyState === 4 && xhr.status === 200) {
    var employees = JSON.parse(xhr.responseText);
    var statusHTML = '<ul class="bulleted">';
    for (var i=0; i<employees.length; i += 1) {
      if (employees[i].inoffice === true) {
        statusHTML += '<li class="in">';
      } else {
        statusHTML += '<li class="out">';
      }
      statusHTML += employees[i].name;
      statusHTML += '</li>';
    }
    statusHTML += '</ul>';
    document.getElementById('employeeList').innerHTML = statusHTML;
  }
};
xhr.open('GET', '../data/employees.json');
xhr.send();



var requestRoomList = new XMLHttpRequest();
requestRoomList.onreadystatechange = function() {
   if(requestRoomList.readyState === 4 && requestRoomList.status === 200) {
          var rooms = JSON.parse(requestRoomList.responseText);
          var statusHTML = '<ul class="rooms">';
          for (var i = 0; i < rooms.length, i++){
              if (rooms[1].available === true){
                  statusHTML += '<li class="empty">';
              } 
              else {
                  statusHTML += '<li class="full">';
              }
            statusHTML += rooms[i].room;
            statusHTML += '</li>';
          }
     statusHTML += '</ul>';
     document.getElementById('roomList').innerHTML = statusHTML;
   }
};

requestRoomList.open( 'GET', '../data/rooms.json');
requestRoomList.send();