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The author will sometimes, if not too busy (and in a good mood), answer general scripting questions.  However, if you have a problem getting a specific script to work, you would be well advised to post to the comp.os.unix.shell Usenet newsgroup.
If you need assistance with a schoolwork assignment, read the pertinent sections of this and other reference works. Do your best to solve the problem using your own wits and resources. Kindly do not waste the author's time. You will get neither help nor sympathy. 
E-mails from certain spam-infested TLDs (61, 202, 211, 218, 220, etc.) will be trapped by spam filters and deleted unread. If your ISP is located on one of these, please use a Webmail account to contact the author.
Well, if you absolutely insist, you can try modifying Example A-46 to suit your purposes.