i have a quick question about eigenvalue/eigenvectors

so say i have a matrix

-3 0

2 -1

with eigen values -1 and -3 (i'm pretty sure they are right)

so for the first eigenvalue (-1) i get a matrix

-2 0

2 0

and for the second (-3)

0 0

2 2

well i not realy sure how to get the eigen vector from these?...wondering if someone could help me...this would really help, thanks