  The exact relation between the response function $R(t,t^{\prime})$ and the
two time correlation function $C(t,t^{\prime})$ is derived analytically in the
one dimensional kinetic Ising model subjected to a temperature quench. The
fluctuation dissipation ratio $X(t,t^{\prime})$ is found to depend on time
through $C(t,t^{\prime})$ in the time region where scaling $C(t,t^{\prime}) =
f(t/t^{\prime})$ holds. The crossover from the nontrivial form
$X(C(t,t^{\prime}))$ to $X(t,t^{\prime}) \equiv 1$ takes place as the waiting
time $t_w$ is increased from below to above the equilibration time $t_{eq}$.
