<script language="javascript">
      function showtab(id){
      names = new Array ("tabname_1","tabname_2","tabname_3","tabname_4","tabname_5"); //массив id заголовков табов
      conts= new Array ("tabcontent_1","tabcontent_2","tabcontent_3","tabcontent_4","tabcontent_5"); //массив id табов
      for(i=0;i<names.length;i++) {
      document.getElementById(names[i]).className = 'nonactive';
      }
      for(i=0;i<conts.length;i++) {
      document.getElementById(conts[i]).className = 'hide';
      }
      document.getElementById('tabname_' + id).className = 'active';
      document.getElementById('tabcontent_' + id).className = 'show';
      }
</script>