Normal Distribution Table

I'm given that:

   Z ~ N(0,1)
   phi(z0) = 0.01
   phi(z1) = 0.025

How do I find z0 and z1, when the smallest value for phi(z) on my Normal Distribution Lookup Table is 0.5000 ?


I recall that my teacher explained a method of doing this a few months back, but cannot seem to remember it..

My guess is something like linking the small value to a larger one which is on the table, and then reversing it later on, perhaps something like this?..

   Z ~ N(0,1)
   phi(z) = 0.01
   phi(z) = 1 - 0.99
   1 - phi(z) = 0.99
   
   Now what?

:\

Thanks !