gre.animation_destroy(id)

function create_animation(mapargs)
    local data = {}

    -- slide the x position 400 pixels over 2000 msec
    id = gre.animation_create(60)
    data["rate"] = "linear"
    data["duration"] = 2000
    data["offset"] = 0
    data["delta"] = 400
    data["key"] = "mylayer.mycontrol.grd_x"
    gre.animation_add_step(id, data)

    -- destroy it
    gre.animation_destroy(id)
end