The National Assn. of Securities Dealers, also suspended Prudential-Bache Securities for 20 business days from making a market in Crown Books Inc., for falsely reporting stock trades. In addition, the association, which regulates over-the-counter stock trading, also said it fined and suspended two Prudential-Bache employees and one former employee. The NASD said Prudential-Bache employees entered fictitious trade reports into the NASDAQ system and failed to report real trades in an effort to support the price of a particular stock. Prudential-Bache and the three current or former employees all accepted the sanctions without admitting or denying the allegations, the NASD said.