<script>
function showlayer(id) {
for (var i= 1 ; i< 6 ; i++) {
document.getElementById('sloy'+i).style.display = (i==id) ? '' : 'none';
}
}
</script>
<table>
<tr>
       <td>
	   <input type="button" value="ñëîé 1" onclick="showlayer(1)"><br>
	   <input type="button" value="ñëîé 2" onclick="showlayer(2)"><br>
	   <input type="button" value="ñëîé 3" onclick="showlayer(3)"><br>
	   <input type="button" value="ñëîé 4" onclick="showlayer(4)"><br>
	   <input type="button" value="ñëîé 5" onclick="showlayer(5)"><br>
	   </td>
       <td>
	   <div style="display: none;" id="sloy1">ñëîé  1 </div>
	   <div style="display: none;" id="sloy2">ñëîé  2 </div>
	   <div style="display: none;" id="sloy3">ñëîé  3 </div>
	   <div style="display: none;" id="sloy4">ñëîé  4 </div>
	   <div style="display: none;" id="sloy5">ñëîé  5 </div>
	   </td>
</tr>
</table>

if (i==id) document.getElementById('sloy'+i).style.display = '';
else document.getElementById('sloy'+i).style.display = 'none';