scroll area index

Im develop a site with the new scrollarea plugin and the default vtourskin generated with the last krapano 1.0.8.15 tools. I need know the current scene index when the pano thumb on the sroll area is clicked. I tried with:
<action name="skin_showlastscene">
add(newsceneindex, scene[get(xml.scene)].index, %1);
txtadd(skin_settings.urlmap, get(skin_settings.urlmap), get(newsceneindex));
openurl(get(skin_settings.urlmap)));
</action>
But the code: scene[get(xml.scene)].index
return a null value,
Help me please.