math problem? Supply and demand? Elasticity?

Shark Inc. has determined that demand for its newest netbook model is given by lnq−5lnp+0.001p=7, where q is the number of netbooks Shark can sell at a price of p dollars per unit. Shark has determined that this model is valid for prices p≥100. You may find it useful in this problem to know that elasticity of demand is defined to be E(p)=dq/dp * p/q

I took the derivative and got dq/dp = (5/p -0.001)q, i then multiplied by p/q, q cancels out and i'm left with E(p) = (5/p - 0.001)p, and p cancels out with 5/p and i'm left with 5-0.001p. but apparently this isn't the right answer, and i have no idea of how to do the second part. please help.