$gelenurl = $_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
$urlparcala=explode("/",$gelenurl);
$urlgelen=$urlparcala[2];

                  <div class="rd-navbar-nav-wrap">
                    <div class="rd-navbar-element">
                    </div>
                    <ul class="rd-navbar-nav">
                      <li class="<?php if($urlgelen=="index.html"){ ?>active<?php } ?>"><a href="index.html">Ana Sayfa</a></li>
                      <li class="<?php if($urlgelen=="hakkimizda.html" OR $urlgelen=="referanslar.html" OR $urlgelen=="uygulamalar.html" OR $urlgelen=="iletisim.html"){ ?>active<?php } ?>"><a href="#">Kurumsal</a>
                        <ul class="rd-navbar-dropdown">
                          <li><a href="hakkimizda.html">Hakkımızda</a></li>
						  <li><a href="referanslar.html">Referanslar</a></li>
                        </ul>
                      <li><a href="uygulamalar.html">Uygulamalar</a>
                      </li>
                      <li><a href="iletisim.html">İletişim</a>
                      </li>
                    </ul>
                  </div>