Prove: If K is normal to H and H is normal to G, show that $\displaystyle aKa^{-1}$ is normal to H for all $\displaystyle a\in G$

Would I say:

$\displaystyle hKh^{-1}=k$ and $\displaystyle aHa^{-1}=h$ then try to get H=K and subsitute the K for H? Or is that way off?

Thanks guys!