<html>
<head>
<meta charset="utf-8">
</head>
<body>
<form action="fooddel.php" method="POST" id='food_del' name="food_del">
<label class="">Ваше имя:</label><br />
<input name="food_name" type="text" id="food_name" size="36"><br />
<label class="">Ваша фамилия:</label><br />
<input name="food_names" type="text" id="food_sname" size="36"><br />
<label class="">Адрес доставка:</label><br />
<input name="food_add" type="text" id="food_add" size="36"><br /><br />
<label class="">Список товаров:</label><br />
<div class="inputs">
<label class="">Товар №1:</label><br />
<input name="food_goods[]" type="text" id="food_goods_one" size="36"><br />
<label class="">Товар №2:</label><br />
<input name="food_goods[]" type="text" id="food_goods_one" size="36"><br />
<label class="">Товар №3:</label><br />
<input name="food_goods[]" type="text" id="food_goods_one" size="36">
<a href="#" id="add" class="btn btn-small btn-primary">Добавить товар</a>
</div>
<input type="submit" name="food_send" class="btn btn-large btn-primary" value="Отправить заявку">
</form>
<script>
i=3
add.onclick=function(){
var s=document.createElement("span")
s.innerHTML='<br /><label class="">Товар №i:'+(++i)+'</label><br /><input name="food_goods[]" type="text" id="food_goods_one" size="36">'
document.querySelector("form div").appendChild(s)
}
</script>
</body>
</html>