<style>	
#menu span {
padding: 7px 15px 7px; 
margin-right: 5px;
margin: 10px 0;
width: 20px;
text-decoration: none;
}
#menu .tabactive {
color: #2662DF;
background:#F9F1DD;
}

#submenu {
padding: 5px;
height: 300px;
text-align: center;
font-size: 12px;
width: 100%;
}

.submenutext {
display: none; 
height: 300px;
}
</style>

<script type="text/javascript">
$(document).ready(function() {
$("td.#MenuTxT div.submenutext").hide();
<!--$(".tabs span:first").addClass("active").show(); -->
$("td.#MenuTxT div.submenutext:first").show();
$("div.#menu span").click(function() {
    $("div.#menu span").removeClass("tabactive");
    $(this).addClass("tabactive");
    $("td.#MenuTxT div.submenutext").hide();
    var activeDiv = $(this).attr("alt");
    $("div."+activeDiv).fadeIn();
    return false; });
});
</script>

<center><table style="width: 615px;">
 <tbody>
  <tr>
   <td>
    <div id="menu"> <b>
<span alt="#sm1" style="cursor: pointer;">Начало</span>
<span alt="#sm2" style="cursor: pointer;">Кнопка 2</span>
<span alt="#sm3" style="cursor: pointer;">Последние сообщения форума</span>
<span alt="#sm4" style="cursor: pointer;">555</span>
<span alt="#sm5" style="cursor: pointer;">ЧАТ</span>
           </b>
    </div>
   </td>
  </tr>
  <tr>
   <td id="MenuTxT"  align="center" valign="top">
    <div id="submenu" align="center"> 
     <div id="sm1" class="submenutext" style="display:block;">
<br/><br/>
<div id=MyDivBlock></div>
</div>
     <div id="sm2" class="submenutext"><br /><br />


Контент 2-й кнопки
</div>
     <div id="sm3" class="submenutext"><br /><br />

</div>
     <div id="sm3" class="submenutext"><br /><br />

</div>
     <div id="sm5" class="submenutext" align=center><br /><br />
<!-- BEGIN CBOX - www.cbox.ws - v001 -->
<div id="cboxdiv" style="text-align: center; line-height: 0">
<div><iframe frameborder="0" width="100%" height="180" src="http://www4.cbox.ws/box/?boxid=3100735&amp;boxtag=7264&amp;sec=main" marginheight="2" marginwidth="2" scrolling="auto" allowtransparency="yes" name="cboxmain" style="border:#000000 1px solid;" id="cboxmain"></iframe></div>
<div><iframe frameborder="0" width="100%" height="82" src="http://www4.cbox.ws/box/?boxid=3100735&amp;boxtag=7264&amp;sec=form" marginheight="2" marginwidth="2" scrolling="no" allowtransparency="yes" name="cboxform" style="border:#000000 1px solid;border-top:0px" id="cboxform"></iframe></div>
</div>
<!-- END CBOX -->
</div>

</div>
   </td>
</tr>
 </tbody>
</table></center>