Z-index problem with dhtmlxcombo in the ligthbox

Hi everyone
How can I define the z-index value of the options container of my combo in the lightbox to make It visible because it appear behind the lightbox
this is the structure of my ligthbox

scheduler.config.lightbox.sections = [
       { name:"patient", options:patients, map_to:"ag_patient", type:"combo", image_path: "./codebase/imgs/", filtering: true, focus:true},
      { name:"description", height:50, map_to:"ag_detail", type:"textarea" },
      { name:"time", height:72, type:"time", map_to:"auto"}

Best regards

Add next style on the page

.dhx_combo_list{ z-index:23000; /* z-index of combo-list */ }

It’s working perfect