option buy land

Hello i am using opensim 7.5 but i have activate also diva so i dont know if now i am in standalone or in grid mode i have add a gridmode = false to the opensim.ini i am using now xoopensim modules with ubuntu and 4 GB ram i have set le helpuri that point to the helper folder ... now my friend ask me to give the owner permission for 1 land when i try to sell at 0 got grey button and no one cant buy land also if i select the person that i want to give the land i have try to find a script for rent but i could not find any i dont know how can resolve now.