How to target an identifier that is not loaded into the DOM?

How to target an identifier that is not loaded into the DOM?

With AJAX, I want to change content of a div. But this div is loaded by another Ajax Script.
This content has a SELECT INPUT. To target, if i use :

  1. $(''#id_select').on('change', function(){---});

#id select isn't found. But if i use :

  1. $('#id_container').on('change', '#id_select', function(){...});

It's ok.

No problem for this.
But then, i have to change html data on a div, with :
  1. $('#search_modele').html(data);

But #search_modele isn't found.
How can i do ?

Thanks a lot for saving my life :)