I have a strange problem that when I click on `special-treatment.html` link, the link is not working? can someboby help me please.

**My html code is here**

```
<div id="navbar-collapse-1" class="navbar-collapse collapse navbar-right">
    <ul class="nav navbar-nav">

        <li class="dropdown"><a href="special-treatment.html" data-toggle="dropdown" class="dropdown-toggle">Special Treatments </a>
            <ul class="dropdown-menu" role="menu">
                <li><a href="psoriasis-treatment.html">Psoriasis Treatment</a></li>
                <li><a href="arthritis-treatment.html">Arthritis Treatment</a></li>
                <li><a href="paralysis-treatment.html">Paralysis Treatment</a></li>
                <li><a href="asthma-treatment.html">Asthma Treatment</a></li>
                <li><a href="diabetes-treatment.html">Diabetes Treatment</a></li>
                <li><a href="hypertension-treatment.html">Hypertension Treatment</a></li>
                <li><a href="facial-paralysis-treatment.html">Facial Paralysis Treatment</a></li>
                <li><a href="cervical-spondylosis-treatment.html">Cervical Spondylosis Treatment</a></li>
                <li><a href="schelerosis-treatment.html">Multiple Schelerosis Treatment</a></li>
            </ul><!-- end dropdown-menu -->
        </li><!-- end standard drop down -->

        <li class="dropdown"><a href="knowledge-base.html" data-toggle="dropdown" class="dropdown-toggle">Knowledge Base  </a>
            <ul class="dropdown-menu" role="menu">
                <li><a href="panchakarma.html">Panchakarma</a></li>
                <li><a href="women-health.html">Women Health</a></li>
                <li><a href="herbs.html">Medicinal Herbs</a></li>
                <li><a href="yoga.html">Yoga</a></li>
                <li><a href="music-therapy.html">Music Therapy</a></li>
                <!--<li><a href="#.html">Appointment Form</a></li>-->
                <li><a href="principles-of-ayurveda.html">Principles of Ayurveda</a></li>
            </ul><!-- end drop down menu -->
        </li><!-- end drop down -->

    </ul><!-- end navbar-nav -->
</div><!-- #navbar-collapse-1 -->

```