[HELP]About the Period Items

Well, My Shop SITE WEB MPOG that is, it works right, all right. More I can not change the period of the items, I tried in dbo.CashShop, Aba 'Duration'. and failed, and vote buying when he buys an item for 3 days.

Below the image below:
http://img199.imageshack.us/i/imagemwlx.png/

I solve most, if I help a lot I appreciate it!

Sorry for the English, I am Brazilian,

the duration column would be for effects of items such as the coins and stuff not for time kept. What you are asking for is in AccountItem.dbo