exactly as Jim said. I do the same thing here
When the session variable for location is not set, I include a file that contains this code;
<div id="noShow">
<a href="#locPromptBox" id="locPromptBoxLink" style="display: none;"></a>
<div id="locPromptBox" class="locPromptBox" data-type="inline">
<p>Please select your Province</p>
<form action="" method="post" enctype="multipart/form-data" name="getLoc" target="_top" id="getLoc">
<p>
<select name="location" id="location">
<option value="ns">Nova Scotia</option>
<option value="nb">New Brunswick</option>
</select>
</p>
<p>
<input type="checkbox" name="remember" id="remember" />
<label for="remember">Remember my choice</label>
(requires cookies)</p>
<p>
<input type="submit" name="submit" id="button" value=" Go " />
</p>
</form>
</div>
</div>
<script type="text/javascript">
//<![CDATA[
$('locPromptBoxLink').cerabox({
group: false,
displayTitle: false,
fixedPosition: true,
clickToCloseOverlay: false,
});
$('locPromptBoxLink').fireEvent('click', '', 100)
//]]>
</script>