problem with dynamic "array key" in smarty

I need to send an array value as a key to another array dynamically in a template.
pls . Help me.

the sample code is as follows:

{foreach name=outer item=hno key=key from=$hoas}
<tr>
<td>
{$hno.sno} //OK

{$be[{$hno.sno}]} //I tried like this -- Wrong

// Here I need to send this {$hno.sno} value as a key to {$be[]} associative array.

</td>
</tr>
{/foreach}