and i create my own code  https://jsfiddle.net/xpwh1oc5/ 

I have two answer :

1 if i change code with [value] the ajax dont work :

2.                 <label class='col-lg-3 control-label'>Inserisci nome dropbox</label>
3.                 <input type="text" id="ricerca_codice_lavorazione[0]" style="color: black"> <button type="button" id="button_ricerca_lavorazione[0]" class="btn btn-info">Ricerca Codice</button>

and ajax too ...

2 , how can i add ajax control for every row added?