NPC for Professions System of Teckman

[Dantarrix]

Well... i find a very useful script of professions, and with it in the base, i imagine a very good idea, a npc that buys all the products or loot of the herbalism...
I have this:

 <?xml version="1.0" encoding="UTF-8" ?> 
- <npc name="Gardener" script="default.lua" speed="110" talkradius="2" walkinterval="2000" floorchange="0">
  <health now="100" max="100" /> 
  <look type="129" head="59" body="120" legs="101" feet="116" addons="0" /> 
- <parameters>
  <parameter key="message_greet" value="Welcome to my shop, adventurer |PLAYERNAME|! I {trade} with herbalism products." /> 
  <parameter key="message_farewell" value="Good bye and come again, |PLAYERNAME|." /> 
  <parameter key="module_shop" value="1" /> 
  <parameter key="shop_sellable" value="fern,2801,2;shadow herb,2804,3;powder herb,2803,4;stone herb,2799,5;sling herb,2802,6;star herb,2800,7; blood herb,2798,8;mushroom,2794,9;dark mushroom,2792,10;white mushroom,2787,11;wood mushroom,2791,12;brown mushroom,2789,13;mushroom,2793,14; orange mushroom,2790,15;fire mushroom,2795,16;" /> 
  </parameters>
  </npc

But when i try to sell something, there appear a message that says: 'You don't have this item'.... I don't know what is wrong... :S
The only thing is that you can only sell 1 item at the time... you can not sell 100 ferns, for example, you need to sell 1 and the another and other and they need to be separadetly