Hello,
you can access controls of the lightbox with following method docs.dhtmlx.com/gantt/api__gantt … ction.html
The code might look following, but i think it would break the layout of the details form
gantt.attachEvent("onBeforeLightbox", function(){
var selects = gantt.getLightboxSection("time").control;//node array of selectboxes
selects[0].setAttribute('size', 5);
return true;
});
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