Getting Bootstrap’s modal content from another page

Update

The way you’re trying to get modal’s content from another page is incorrect.

According to Bootstrap’s documentation:

If a remote URL is provided, content will be loaded one time via
jQuery’s load method and injected into the .modal-content div. If
you’re using the data-api, you may alternatively use the href
attribute to specify the remote source. An example of this is shown
below:

<a data-toggle="modal" href="https://stackoverflow.com/questions/32958219/remote.html" data-target="#modal">Click me</a>

So, firstly, you should change your menu.html file to be similar to the code above:

<li><a href="https://stackoverflow.com/questions/32958219/Lab6.html" data-target="#theModal" data-toggle="modal">Lab 6</a></li>

And then, part of your Lab6.html page must reside inside your menu.html page. E.g:

<div class="modal fade text-center" id="theModal">
  <div class="modal-dialog">
    <div class="modal-content">
    </div>
  </div>
</div>

Finally, your LAB6.html would have only the code that was inside .modal-content. E.g:

<div class="modal-header">
  <button type="button" class="close" data-dismiss="modal">X</button>
  <h1>Lab 6</h1>
</div>
<div class="modal-body">
  <div class="panel panel-default">
    <div class="panel-heading text-center">
      Employee Information
    </div>
    <div class="panel-body">
      <div class="row">
        <div class="text-right col-xs-2">Title:</div>
        <div class="text-left col-xs-3" id="title"></div>
        <div class="text-right col-xs-2">First:</div>
        <div class="text-left col-xs-3" id="firstname"></div>
      </div>
      <div class="row">
        <div class="text-right col-xs-2">Phone#</div>
        <div class="text-left col-xs-3" id="phone"></div>
        <div class="text-right col-xs-2">Email</div>
        <div class="text-left col-xs-3" id="email"></div>
      </div>
      <div class="row">
        <div class="text-right col-xs-2">Dept:</div>
        <div class="text-left col-xs-3" id="departmentname"></div>
        <div class="text-left col-xs-2">Surname:</div>
        <div class="text-left col-xs-4">
          <input type="text" placeholder="enter last name" id="TextBoxLastName" class="form-control" />
        </div>
      </div>
    </div>
  </div>
  <div class="modal-footer">
    <div class="panel-footer">
      <input type="button" value="Find Employee" id="empbutton" />
      <div class="col-xs-10" id="lblstatus"></div>
    </div>
  </div>
</div>

Take a look at the plnkr I created for you.