Lua NPC Shop by script

[Misterion]

Hello everyone!
I want to make a shop in script of the npc (In LUA, not XML). Because like the member FilipeJF said, my source had a big problem with that.
So, I want a simple NPC Shop (NPC who BUY things and SELL things too). I want to make him OPEN a Trade Windown, normally, but by Scripts, not with the normal "Shop_sellable" function into XML.

Thank you.

 

[Limos]

You can use the runes.lua from eryn as example, if you still have problems, post which server you use and what the npc should buy/sell.