The article "Schools in Quandary on AIDS, Condoms," Oct. 9, examines the dilemma schools are in over ways to stem the expanding AIDS tragedy among sexually active teenagers. To curb the spread of the disease, condoms are being offered as a preventative device. But they also are regarded as tacitly condoning sex.As youngsters are encouraged to "Just Say No" to drugs, single teenagers can be prodded to "Just Say No" to sex. Total abstinence for unmarried couples may require a struggle, but the rewards - freedom from AIDS and peace of mind - surely make a prayerful effort to abstain really worthwhile. Our youth's sexual activity needs to be curbed in order to halt the spread of AIDS among them. Charles F. Rasoli, Long Island City, N.Y. Letters are welcome. Only a selection can be published, subject to condensation, and none acknowledged. Please address them to "Readers Write," One Norway St., Boston, MA 02115.