ho risolto in questo modo:

codice:
<script type="text/javascript">
<!--
function xre(x) {
if (x == 1) {
document.getElementById("crost1").innerHTML=1;};
else if (x == 2) {
document.getElementById("crost1").innerHTML=2;};
else if (x == 3) {
document.getElementById("crost1").innerHTML=3;};
document.getElementById("content").style.display="none";
document.getElementById("content2").style.display="block"; }
function xre2(y) {
if (y == 1) {
document.getElementById("crost2").innerHTML=1;};
else if (y == 2) {
document.getElementById("crost2").innerHTML=2;};
else if (y == 3) {
document.getElementById("crost2").innerHTML=3;};
document.getElementById("content2").style.display="none";
document.getElementById("content3").style.display="block"; }
function xre3(z) {
if (z == 1) {
document.getElementById("crost3").innerHTML=1;};
else if (z == 2) {
document.getElementById("crost3").innerHTML=2;};
else if (z == 3) {
document.getElementById("crost3").innerHTML=3;};
document.getElementById("content3").style.display="none";
document.getElementById("content").style.display="block";
}
// -->
</script>
<table>
<tr>
<td id="crost1">0</td>
<td id="crost2">0</td>
<td id="crost3">0</td>
</tr>
</table>
<style type="text/css" media="screen">
#content2, #content3 { display:none; }
</style>
<div id="content">
<input type="button" value="1" onclick="xre(1);">
<input type="button" value="2" onclick="xre(2);">
<input type="button" value="3" onclick="xre(3);">
</div>
<div id="content2">
<input type="button" value="1" onclick="xre2(1);">
<input type="button" value="2" onclick="xre2(2);">
<input type="button" value="3" onclick="xre2(3);">
</div>
<div id="content3">
<input type="button" value="1" onclick="xre3(1);">
<input type="button" value="2" onclick="xre3(2);">
<input type="button" value="3" onclick="xre3(3);">
</div>
però funziona solo su ie... soluzioni?