
Then, learning that her beloved mother has committed suicide, Tracy rushes to New Orleans and discovers that mom had lost her modest auto-parts business to a bunch of gangsters. Played by the strikingly attractive Madolyn Smith (''Urban Cowboy,'' ''All of Me''), Tracy Whitney is a sweet New York bank employee on the verge of marrying the very wealthy investment-house scion who has made her pregnant. ''If Tomorrow Comes'' is really two different movies, the first three hours connected to the rest in name only. Don't give the spectator a moment to think about what is happening. Sheldon, evidently, simple logic is something that closes on Saturday night. Hopping from New York to New Orleans to London and several other European points, the story is an almost pure exercise in titillation marketing. That, at least, might be one of the more charitable ways to account for Sidney Sheldon's ''If Tomorrow Comes,'' the seven-hour production beginning on CBS tomorrow, from 8 to 11 P.M., and continuing Monday and Tuesday, beginning at 9 each evening.



Falling about with laughter, they turn to an unsmiling gentleman nearby and shout, ''Sidney, take it, it's yours, make a million.'' Sitting around pool side at the hotel, a bunch of Hollywood sitcom writers decide to amuse themselves by concocting the silliest mini-series plot they can imagine.
