Dropdown dan modul bootstrap ngk berfungsi

Saat dropdown n modul bootstrap tiba" ngk berfungsi apanya yg bermasalah yah? Soalnya semalam smua baik" sja n berfungsi dgn baik.

Kok tiba" ngk berfungsi??

 <nav class="navbar navbar-default navbar-static-top" role="navigation" style="margin-bottom: 0">

<div class="navbar-header">
  <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
    <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
   </button>

<a class="navbar-brand" href="../halutama.html">SISTEM MONITORING NILAI</a>
</div>

<!-- /.navbar-header -->
<ul class="nav navbar-top-links navbar-right">
  <li><a href="../masuk.html">
     <i class="fa fa-sign-out fa-fw"></i>Keluar</a>
  </li>
</ul>

<!-- /.navbar-top-links -->

<div class="navbar-default sidebar" role="navigation">
  <div class="sidebar-nav navbar-collapse">
  <ul class="nav" id="side-menu">
    <li><a href="../halutama.html"><i class="fa fa-home fa-fw"></i> HALAMAN UTAMA</a>
    </li>
    <li><a href="admin.html"><i class="fa fa-user fa-fw"></i> DAFTAR PENGGUNA</a>
    </li>
    <li><a href="#"><i class="fa fa-sitemap fa-fw"></i> NILAI JURUSAN<span class="fa arrow"></span></a>

<ul class="nav nav-second-level">
    <li><a href="#">ELEKTRO <span class="fa arrow"></span></a>
                                    <ul class="nav nav-third-level">
                                    <li><a href="PTIK.html">PTIK</a></li>
                                        <li><a href="elektro.html">ELEKTRO</a>
 </li>
                                    </ul>
                                </li>

<li><a href="ptsp.html">PTSP</a></li>
<li><a href="mesin.html">MESIN</a>
</li>
<li><a href="otomotif.html">OTOMOTIF</a>
</li>

</ul>
  <!-- /.nav-second-level -->
  </li>
  <li>
 <a href="../forms.html"><i class="fa fa-edit fa-fw"></i> REKAP NILAI</a>
  </li>
<!-- /.nav-second-level -->
                    </ul>
                </div>
    <!-- /.sidebar-collapse -->
            </div>
   <!-- /.navbar-static-side -->
        </nav>

    <!-- Page Content -->
    <div id="page-wrapper">
   <div class="container-fluid">
<div class="row">
<div class="col-lg-12">
 <h3 class="page-header">Daftar Akun Pengguna</h3>
<!-- ini modal dengan tombol-->
				<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#mymodal">Tambah Baru</button>
<br>
<!--Modal-->
<div id="mymodal" class="modal fade" role="dialog">
<div class="modal-dialog">

					<!--isi modal-->
					<div class="modal-content">
					<div class="modal-header"><button type="button" class="close" data-dismiss="modal">×</button>
						<h4 class="modal-title">Tambah Akun Baru</h4></div>
							<div class="modal-body">
								<!--Tabel dimulai dari sini-->
										<div class="row">
                               				<div class="form-group form-group-sm">
													<div class="col-lg-2"><label>Nama:</label></div>
                                        			<div class="col-lg-4"><input class="form-control" placeholder="Enter text"></div>
                                         			<div class="col-lg-2"><label>Username:</label></div>
                                         			<div class="col-lg-4"><input class="form-control" placeholder="Enter text"></div>
		          								</div>
                   							</div>
                   						<br>

                 							<div class="row">
                                				<div class="form-group form-group-sm">
                                         			<div class="col-lg-2"><label>Keterangan:</label></div>
													<div class="col-lg-4"><input class="form-control form-group-sm" placeholder="Enter text"></div>
                                         			<div class="col-lg-2" align="left"><label>Password:</label></div>
													<div class="col-lg-4"><input class="form-control" placeholder="Enter text"></div>
												</div>
                   							</div>
                   						<br>

										<div class="row">
										<div class="col-lg-offset-10">
										<button type="button" class="btn btn-success"><i class="glyphicon glyphicon-save"></i> Simpan</button>
											</div>
										</div>                  				</div>
					</div>				</div>
				</div>