themechanger.tpl для simpla

<div style="width:100%; height:26px; background-color:#000; color:#FFF; position: fixed;">
<form method="post" id="ThemeChanger" >
<input type=hidden name="action" value="set_main_theme">
<select name="theme">';
{foreach $themes as $th}
<option value="{$th->name}" {if ($th->name == $theme->name)}selected{/if} >{$th->name}</option>
{/foreach}
</select>
<input type="submit" value="Сменить тему" onClick="window.location.reload();" />
</form>
</div>