좌측메뉴를 생성하였습니다

메뉴 누르면 그에따라서 메뉴의 색이 바뀌게 하고싶은데...ㅠㅠ

이걸 if문으로 어떻게 해야할지 막막하네요 ㅠㅠ

고수님들의 조언부탁드립니다 ㅠㅠ

    <ul class="s_menu_list">
      <? $site_url = $PHP_SELF;

          if($site_url == "sub1_02.html"){ ?>
     <li class="s_m"><a href="javascript:menu1sub1();">인사말</a></li>
     <li class="s_m_"><a href="javascript:menu1sub2();">연혁</a></li>
     <li class="s_m"><a href="javascript:menu1sub3();">오시는길</a></li>
    <? }elseif($site_url == "sub1_03.html"){ ?>
     <li class="s_m"><a href="javascript:menu1sub1();">인사말</a></li>
     <li class="s_m"><a href="javascript:menu1sub2();">연혁</a></li>
     <li class="s_m_"><a href="javascript:menu1sub3();">오시는길</a></li>
    <? }else{ ?>
     <li class="s_m_"><a href="javascript:menu1sub1();">인사말</a></li>
     <li class="s_m"><a href="javascript:menu1sub2();">연혁</a></li>
     <li class="s_m"><a href="javascript:menu1sub3();">오시는길</a></li>
    <? } ?>
    </ul>
​

혹시몰라 링크를 걸어둡니다 ㅠㅠ