  In this paper we demonstrate how the recently reported exactly and
quasi-exactly solvable models admitting quasinormal modes can be constructed
and classified very simply and directly by the newly proposed prepotential
approach. These new models were previously obtained within the Lie-algebraic
approach. Unlike the Lie-algebraic approach, the prepotential approach does not
require any knowledge of the underlying symmetry of the system. It treats both
quasi-exact and exact solvabilities on the same footing, and gives the
potential as well as the eigenfunctions and eigenvalues simultaneously. We also
present three new models with quasinormal modes: a new exactly solvable
Morse-like model, and two new quasi-exactly solvable models of the Scarf II and
generalized P\"oschl-Teller types.
