How to show that for small oscillations, the motion of a simple pendulum is simple harmonic??? please reply ASAP!!!!

For small angles, the time period is given as 

T = 2π.(l/g)^1/2 

It is simple harmonic because it is of the form 

T = 2π.(M/g)^1/2 

which is equation of time period of an object in SHM.