Why isn't my code working?

var xhr = new XMLHttpRequest ();
xhr.open('GET', 'data/employees.json');
xhr.onreadystatechange = function () {
    if(xhr.readyState === 4) {
        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.send();