When I try to change a file value and save it the new field value is not kept I get back the old value when I refresh page. Here is my field code :

$col = array();
$col["title"] = "Responsable";
$col["name"] = "nom_pere";
$col["width"] = "18";
$col["editable"] = true; // this column is editable
$col["hidden"] = false;
$cols[] = $col;

Thanks !