#menu {
text-align: justify !important;
border: 2px solid #0cc0cc;
width: 970px;}

<style>
#menu {
text-align: center !important;
border: 2px solid #0cc0cc;
width: 840px;}

#menu span {
margin: 0px 10%;
padding: 0px;
border: 2px solid #000;
}

#submenu {
border: 2px solid #ccc;
padding: 30px 0 0 0;
width: 840px;
height: 350px;}

.submenutext {
padding: 25px 30px 25px 30px;
display: none;
text-align: center;
height: 250px;
width: 740px;}
</style>
<table style="width: 970px;" border="0" cellpadding="0" cellspacing="0">
 <tbody>
  <tr>
   <td align="center" valign="top">
    <div id="menu">
<span alt="#sm1" style="cursor: pointer;">1 кнопка</span> 
<span alt="#sm2" style="cursor: pointer;">2 кнопка</span>
<span alt="#sm3" style="cursor: pointer;">3 кнопка</span></div></td></tr>
  <tr height="300">
   <td id="MenuTxT"  align="center" valign="top">
    <div id="submenu" align="center"> 
     <div id="sm1" class="submenutext" style="display:block;"><br/>
Контент кнопки новостей
</div>

<div id="sm2" class="submenutext"><br/>
Контент кнопки админов
</div>

<div id="sm3" class="submenutext"><br/>
Контент кнопки навигации
</div>

</td></tr></tbody></table>

<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>