Hello,
$("selector").trigger("sortupdate");
you will have to pass as second argument of a function where to put in the event and the ui, event is not as important as ui
the inside code of the sortable widget for event triggering looks like this
this._trigger("update", event, this._uiHash(this));
So you may want to do following
function triggerUpdateFor(selector) {
var widget = $(selector).sortable("widget");
if (widget) widget._trigger("update", null, widget._uiHash(widget));
}
Hope this work!!