7.4 Bootstrap - Modal windows

<!-- These are already included. Let's not include these here. <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"></link> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script> --> <button type="button" class="btn btn-info btn-md" data-toggle="???" data-target="???">Open SignIn</button> <div class='??? fade' id='tr1-modal' role='dialog'> <div class='modal-dialog'> <div class='modal-???'> <form class="form-horizontal"> <div class='modal-???'> <h2 class='modal-title'>SignIn</h2> </div> <div class='modal-???'> <div class="form-group"> <label class="control-label" for="username">Username:</label> <input type="text" class="form-control" id="username" placeholder="Enter username"> </div> <div class="form-group"> <label class="control-label" ???="password">Password:</label> <input type="password" class="form-control" id="password" ???="Enter password"> </div> </div> <div class='modal-???'> <div class="form-group"> <button type="cancel" class="btn btn-default" data-dismiss="modal">Cancel</button> <button type="submit" class="btn btn-default">Submit</button> </div> </div> </form> </div> </div> </div> Submit