gistfile1.html

/* FORM */
<form action="/topics" id="new_topic_form" method="post" onsubmit="new Ajax.Request('/topics', {asynchronous:true, evalScripts:true, method:'post', onComplete:function(request){Form.Element.enable('add_topic_submit')}, onLoading:function(request){Form.Element.disable('add_topic_submit')}, parameters:Form.serialize(this)}); return false;">
	<div style="margin:0;padding:0;display:inline">
		<input name="authenticity_token" type="hidden" value="6sukkqZzoOtj09Z/vJvkgn00m5PrbdjG3n7DFffaQA0=" />
	</div>
	<input id="topic_slideshow_id" name="topic[slideshow_id]" type="hidden" value="107" />
	<label for="topic_title">Title</label>
	<br />
	<input id="new_topic_title_field" name="topic[title]" size="30" type="text" />
	<br />
	<input class="button" id="add_topic_submit" name="commit" type="submit" value="Add Topic" />
</form>

gistfile2.js

/* Javascript */
function show_hidden_box(box_id){
	$(box_id).slideDown({duration: 0.6});
}

function show_hidden_box_and_focus(box_id, focus_on_field){
	show_hidden_box(box_id);
	$('new_topic_title_field').activate();
}