Finding kinetic energy in Simple harmonic motion?

A light spring is suspended from a rigid support and its free end carries a m of 0.40 kg, which produces a static extension of 0.06m in the spring. The m is pulled down a further 0.06m and released. The m then oscillates with simple harmonic motion. By considering all energy changes involved, calculate the kinetic energy of the m as it pes through the mid point of its motion.