19.03.2015, 13:56
Make a player variable to check if the owner has a house or not. When he sells the house you set it to zero so he can't sell a house he doesn't own.
if(ownshouse[playerid] == 0) return SCM(playerid, COLOR_LIGHTRED, "You do not own a house.");
if(ownshouse[playerid] == 0) return SCM(playerid, COLOR_LIGHTRED, "You do not own a house.");