[Siralos]

Well, the question is not very clear...
For deleting the object I would do:

Код:

CMD:createobject(playerid, params[])
{
    new object = CreateObject(...);
    SetTimerEx("DeleteObject", 15000, 0, "i", object);
}

forward DeleteObject(object);
public DeleteObject(object)
{
    DestroyObject(object);
}