Why is my if (!found) loop not displaying the alert message?

var message = '';
var student;
var search;
var found = false;

function print(message) {
  var outputDiv = document.getElementById('output');
  outputDiv.innerHTML += message;
}

function getStudentReport( student ) {
    var report = '<h2>Student: ' + student.name + '</h2>';
    report += '<p>Track: ' + student.track + '</p>';
    report += '<p>Achievements: ' + student.achievements + '</p>';
    report += '<p>Points: ' + student.points + '</p>';
    return report;
}

while (true) {
  search = prompt("Search student records: Type a name [Luke] (or type 'quit' to end");
  if ( search === null || search.toLowerCase() === 'quit' ) {
    break;
  } 
  for (var i = 0; i < students.length; i += 1) {
    student = students[i];
    if ( search === null || student.name === search ) {
      alert('Name: \'' + search + '\' was found.');
      message = getStudentReport( student );
      print(message);
      found = true;
    }
  }
  if (!found) {
    alert('Name: ' + search  + ' was not found.');
  }
}