<input _last="" name="_code_id_edit" id="_code_id_edit" size="12" maxlength="10" value="" class="combo3" rel="code_id" autocomplete="off" title="" type="text">$opts['max'] should be 20 instead of default 10 in your case in Lines 282 to 287 of includes/ui/ui_lists.inc:
$edit_entry = "<input $disabled type='text' name='$search_box' id='$search_box' size='".
$opts['size']."' maxlength='".$opts['max'].
"' value='$txt' class='$class' rel='$name' autocomplete='off' title='"
.$opts['box_hint']."'"
.(!fallback_mode() && !$by_id ? " style=display:none;":'')
.">\n";