property cursorData

This property gets or sets the 'current' selectable box for a select box. The SelectedData structure is defined below. Returns null object if no current item.
See the SelectionData object for more information.

function onSample()
{
    var list = scene.getBoxById("list");
    if (list)
    {
        var selectedData = list.cursorData.value;
        if (selectedData)
        {
            // Do something.
        }
    }
}