Write a function to compute the n-th partial sum of the alternating series
            
1-1/(4)+1/(9)-1/(16)+...+(-1)^(n-1)*1/(n^(2))

Specifically, the procedure takes n as input, and returns the sum of the first n terms. 

Can someone help me with this? I'm not very good at using procedures.

 G := proc (N)

 local s, n;

 s := 0.;

 n := 0;

 while n < N do 

n := n+1;

 s := s+1/n

 end do;

 [s, n] 

end proc;

             G := proc (N) local s, n; s := 0.; n := 0; while n < N do n := n+1; s := s+1/n end do; [s, n] end proc
Compute  G(1.0),G(2.0), .....G(7.0)   try to figure out what the procedure G is doing

> G(1.0);