Consider the Following Two Player Game, Where "A" Through "H

Consider the following two player game, where "a" through "h" are all greater than zero:
$\begin{array}{l}~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\text { Player } 2\\\begin{array}{c} && \text { Left } && \text { Right } \\& \text { Top } & a, b && c, d \\\text { Player 1 } & \text { Bottom } & e, f && g, h\end{array}\end{array}$
(a) What conditions must we impose on the values of a through h to make both {Top, Left} and {Bottom, Right} Nash equilibria of this game? (b) What additional conditions must we impose on the values of a through h to make {Top, Left} a payoff dominant Nash equilibrium?