Repopulate multi select list

Hi I am having difficulty populating a multi select list section in the lightbox. I can repopulate the select using the code below but it errors(cannot read property ‘options’ of undefined) when I try doing the same code for a multi select.

Thanks for any help!

//Populate only the Instructors that are linked to the Topic Selected
var lstTopicsInstructorLink = filterOptions(scheduler.serverList(“instructor_topic_link”), “link”, value);

if (lstTopicsInstructorLink.length > 0){
update_select_options(scheduler.formSection(‘Lead Instructor’).control, lstTopicsInstructorLink);
scheduler.formSection(“Lead Instructor”).control.disabled = false

    update_select_options(scheduler.formSection('Instructor').control, lstTopicsInstructorLink);
scheduler.formSection("Instructor").control.disabled = false */

}else{
lstTopicsInstructorLink.unshift({key:null, label:“No Instructor Linked to Topic.”}); //insert first section
scheduler.formSection(“Lead Instructor”).control.disabled = false

    //multi select section				
update_select_options(scheduler.formSection('Instructor').control, lstTopicsInstructorLink);
scheduler.formSection("Instructor").control.disabled = false

}

Hi,

Please reproduce the error using the DHTMLX snippet system. It will help me to understand what goes wrong and how to fix. http://snippet.dhtmlx.com/8efe9acfc
Just update code to get the same issue, then click on Share button and send me new link.