add options to select on lightbox

can i dynamically add option to default lightbox ??

i getting value throws onchange

{ name: "select", height: 21, map_to: "course_type", onchange:function(id){ appenChild(id.currentTarget.value);}, type: "select", options: course_type }, { name: "auditory", height: 21, map_to: "audi_type", type: "select", options: auditory_type },

and than with selected value add new option on ligthbox to auditory_type

done by combo over DB.