{style}
{literal}
    .ow_fb_button_icon .fb_button_small {
	width: 18px;
	height: 18px;
	padding: 0px;
    }
{/literal}
{/style}

<div class="ow_fb_button_icon">
    <a class="fb_button fb_button_small" onclick="OW_FB.login(); return false;">&nbsp;</a>
</div>