Somme news :
I made a simplier script : <script type="text/javascript"> $(document).ready(function(){$(".txtSerial").click(function () { $ (this).autocomplete("./serieComplete.php", {max: 10, scrollHeight: 220, mustMatch: true}).result(function(){alert($(this).attr ("id"));} ); });}); </script> and I found out that in fact it work fine on IE but not on FF. Any idea ?