(FORTUNE Magazine) – When a stranger calls wanting to sell you securities, you can, of course, simply hang up. But mother taught you to be polite, and so you wind up trying some riposte that sounds cunning to you but for which the caller proves to be fully prepared. For example: ''Sorry, my brother/son/grandmother is a broker.'' Back will come: ''Don't you think it's rather foolish for you to be investing through someone so close to you?'' Or: ''I'm sure he/she doesn't have a monopoly on good investment ideas.'' In short, what you need are more sophisticated methods of rejection or obfuscation, and here are a few to consider: -- If you have the skill, slip immediately into your second language and very earnestly and politely ask the caller to repeat everything he says, which will drive him nuts long before it does you: ''Merreel Leench? Merreel Leench? Il me semble que j'ai entendu parler de ca mais . . . alors, votre nom, c'est Smeeth? S-M-E-E-T-H?'' -- Since these complete strangers always use your first name and you at least want to feel morally superior, take a tip from Miss Manners: ''I'm so sorry, but I don't believe we've met. So there must be some confusion. You see, Mildred is my first name. My surname is Case, and you may call me Mrs. Case.'' -- If you have not yet admitted to being yourself and can pass as a butler, try: ''I'm sorry, but Mr. Carruthers has just left for six months in Europe.'' -- If you can stand the repeat calls this admission of wealth will spawn: ''I'm sorry, but J.P. Morgan handles my money and they're doing quite nicely.'' -- If your good manners are wearing thin: ''Pardon me, but before you go any further, may I please have your home telephone number. I want to call you at home when you're sitting down to dinner with your family. Seems only fair, doesn't it?'' -- If you are at the office, and the caller has asked breezily for Bill Wilson: ''Do you know Mr. Wilson? Oh, you do. Well, then, I think you had better revise your list because Mr. Wilson has been dead for three years.'' -- The second-best rejection: ''We went into Chapter 11 today.'' -- The ultimate rejection: ''Oh, you mean this is a moneymaking idea? Sorry, but I've got all the money I need.''