If you've ever seen a batch of letters sent in response to a want ad, you know they can be hysterically funny. A random sampling usually demonstrates every mistake in the book (like sending the letter to the wrong company). Here are twenty-eight common errors to avoid:

1. Addressing letters, "Dear Sir:" or "Dear Sirs:" As you know, many readers today are women. If gender is unclear, the salutation should be something like "Dear Hiring Manager," or "Dear Human Resources Manager."

2. Addressing letters, "To whom it may concern." Find out who will receive the correspondence, and address it personally. We received a letter addressed to "Dear Whomever," to which one consultant replied, "I'll answer to anything but this!"

3. Enclosing a photo. Skip the photo unless you're a model or an aspiring actor.

4. Handwriting or typing over an old resume or letterhead. If you've moved, start over. Changes on old documents aren't acceptable.

5. No signature. Even if you type your name at the end of correspondence, you should sign the page in your own handwriting to give it a personal touch.

6. Spelling errors. One applicant said he was well suited for "writting and editing chores... contac t (sic) me at the adrwss (sic) below." Would you give him your editing work? Another writer said she would enjoy "hearing form (sic) us." Word processing spell checkers make mistakes; so proof everything.

7. Not checking grammar. One person wrote, "It sounds exciting and give me (sic) the opportunity to use my skills." Check your letters for correct sentence structure. Have friends review them too.

8. Handwriting letters. Brief 30-word thank you notes can be handwritten, if legible. All other correspondence should be typewritten or word processed, even if you have to borrow a word processor or pay a secretarial service. Handwritten letters don't say "business."

9. Using a Post-It Brand Note as a letter. Post-It Brand Notes aren't letters. Using one says, "This isn't important. I was too busy to write a real letter."

10. Using the word "I" too much. Some letters are filled with 20 or 30 Is. Make sure yours aren't. Advertising is about "you." Emphasize "you" rather than "I."

11. FAXing letters unexpectedly.

12. Forgetting to include your phone number. One woman wrote, "Please call me at home," but didn't include a phone number. That looked bad.

13. Cluttered desktop publishing. With the advent of PCs, some job seekers feel the urge to "be creative" using various type sizes and fonts. Avoid this in business correspondence. Except in rare cases, business letters should look conservative. If you want to be creative, do so in your choice of words. Save Microsoft Publisher and Corel Draw for your Christmas cards.

14. Using a post office box as an address. Except in rare cases, such as conducting a confidential job search, use a street address. Post office boxes seem "transient."

15. Oddball phrasing, such as "an opportunity to expand my strengths and delete my weaknesses... " Or, "You may feel that I'm a tad overqualified." Or, "Enclosed herewith please find my resume." Do you talk that way? You should write the way you talk. Avoid bad phrasing by having others critique your letters.

16. Typos, like "thankyou for your assistance."

17. Mailing form letters. Some letters contain "fill in the blanks." Generic forms don't work well.

18. Not saying enough. One want ad letter read, "Please accept my enclosed resume for the position of Executive Director. Thank you." That's too short. A letter is an opportunity to sell. So say something about yourself.

19. Ending with "Thank you for your consideration." EVERYONE ends their letters this way, so please don't. Try something different, like "I'm excited about talking further," or "I know I could do a good job for you." The same goes for "Sincerely," and "Sincerely yours." EVERYONE uses them. Find something different like "Good wishes," "With best regards," or "With great enthusiasm."

20. WRITING IN ALL CAPS. IT'S HARD TO READ. DON'T DO IT.

21. Abbreviating Cir., Ave., Dec., and all other words. Take time to spell words out. It looks so much better.

22. Forgetting to enclose your resume. If you say you're enclosing one, then do.

23. Justifying right margins. When you "justify right," you create large gaps between words inside your sentences.

24. Forgetting the date and/or salutation.

25. Using dot matrix printers. Most are hard to read and they make you look like an engineer. Whenever possible, use a laser printer, even if you have to borrow one.

26. Talking nonsense. "I work in instilling proper conduits for mainstream educational connections while also encouraging individual creative forms." What? Run that one by me again.

27. Forgetting to put the letter in the envelope. (I received an empty FedEx package yesterday.)

28. The 300-word paragraph. The worst mistake in marketing is writing too long. Limit sentences to seven or eight words, and limit paragraphs to four or five lines. In letter writing, short is usually better. I try to limit my own letters to one page, seldom two. I believe if I can't say it well in one page, I probably can't say it well at all.

29. Bonus tip from Laurie Schell. In an e-mail to me she said, "I thought you may want to add a number 29. As a manager my boyfriend reads a lot of cover letters and complains when he receives them with really small font. Even a regular size font is hard to read if he has forgotten his glasses that day, and so small-font letters are immediately dismissed."

William S. Frank, M.A., is founder and President of CareerLab. For more information about CareerLab, visit www.careerlab.com.