当关注表单中的最后一个输入时自动添加行

我被困在项目的一部分，用户应该继续填写表单，当用户关注表单中的最后一个输入时，应该自动添加新行。我不擅长JS/jQ，所以也许你们中有人可以帮助我…它正在工作，但仍然只是从第一行，而不是从重复的。Thanks is advance

<form class="form-inline" method="post" action="loadin.php">
    <!-- form header -->
    <hr>
    <div class="form-group">
        <select class="form-control" name="vendor" id="vendor">
            <?php 
                foreach($vendors_ as $v){
                    echo"<option value='".$v['ID']."'>".ucfirst($v['name'])."</option>";
                } 
            ?>
        </select>
        <input type="text" class="form-control" name="invoice" id="invoice" placeholder="Faktrura">
        <input type="text" class="form-control" name="date" id="date" placeholder="Datum" value="<?php echo date("Y-m-d") ?>">
        <button type="submit" name="LoadItems" class="btn btn-default"><i class="fa fa-check" aria-hidden="true"></i> Nahrát</button>
    </div>
    <hr>
    <!-- form lines -->
    <div class="duplicate" style="margin-bottom: 5px;">
        <div class="form-group">
            <input type="hidden" class="form-control cleanVal" name="row[]"       id="row">
            <select class="form-control" name="category[]" id="category">
                <?php 
                    foreach($types_ as $t){
                        echo"<option value='".$t['ID']."'>".ucfirst($t['name'])."</option>";
                    } 
                ?>
            </select>
            <input type="text" class="form-control cleanVal" name="item[]"    id="item"    placeholder="Položka">
            <input type="text" class="form-control cleanVal" name="package[]" id="package" placeholder="Balení">
            <input type="text" class="form-control cleanVal" name="amount[]"  id="amount"  placeholder="Množství">
            <input type="text" class="form-control cleanVal" name="price[]"   id="price"   placeholder="Cena">
            <input type="text" class="form-control cleanVal" name="atest[]"   id="atest"   placeholder="Atest">
            <input type="text" class="form-control cleanVal" name="batch[]"   id="batch"   placeholder="Sarže">
            <input type="text" class="form-control cleanVal" name="expire[]"  id="expire"  placeholder="Expirace"   style="width:80px">
            <input type="text" class="form-control cleanVal x" name="vat[]"   id="vat"     placeholder="DPH"        style="width:45px">
        </div>
    </div>
</form>

$(".duplicate:last input").focus(function() {
    count++;
    var $clone = $('.duplicate:last').clone();
    $clone.find("input,select").each(function(){
        $(this).attr({
            id: $(this).attr("id") + count,
        });
    });
    $("form").append($clone);   
    $(".duplicate:last .cleanVal").val('');