Change attribute radio into button similar to add to cart in product.tpl

[Orwa]

Hello, i am using PS 1.6 and I would like to change the "radio" buttons for variations in product.tpl to be a buttons like the ''add to cart" button, the code to change this is as per the following:

{elseif ($group.group_type == 'radio')}
	<ul>
	{foreach from=$group.attributes key=id_attribute item=group_attribute}
<li>
 <input type="radio" class="attribute_radio" name="{$groupName|escape:'html':'UTF-8'}" value="{$id_attribute}" {if ($group.default == $id_attribute)} checked="checked"{/if} />
	<span>{$group_attribute|escape:'html':'UTF-8'}</span>
</li>
{/foreach}
	</ul>
	{/if}

Wrapping it into a div did not work, I am new to html.