var this_tab = tabs.find('#' + this_panel.prop('id') + '_tab');
// if this is the last panel, make a new one
if (this_panel.next().length == 0) {
var this_tab = tabs.find('#' + this_panel.prop('id') + '_tab');
// if this is the last panel, make a new one
if (this_panel.next().length == 0) {