Hiring managers don't want to hear a lot of things during an interview – confessions of a violent past, a cell phone ring, a toilet flush. Yet job seekers have committed these interview gaffes and worse, according to CareerBuilder.com's annual survey of the worst interview mistakes.

Odd behavior isn't the only way to ruin your chances of landing a job. When hiring managers were asked to name the most common and damaging interview mistakes a candidate can make, 51 percent listed dressing inappropriately. Forty-nine percent cited badmouthing a former boss as the worst offense, while 48 percent said appearing disinterested. Arrogance (44 percent), insufficient answers (30 percent) and not asking good questions (29 percent) were also top answers.

 
To ensure your interview is smooth and error-free, follow these five tips.

 
Do some research: When you walk into a job interview, knowledge of the company's history, goals and current activity proves to the interviewer that you are not only prepared for the interview, but also that you want to be a part of the organization.

Don't lie: If the conversation drifts to a topic you're not knowledgeable about, admit you don't know the answer and then explain how you would go about finding a solution. Displaying your problem-solving skills is better than babbling about something you don't understand.

Keep it professional: Although interviewers often try to create a comfortable setting to ease the job seeker's nerves, business decorum shouldn't disappear. Avoid offering personal details that can be controversial or have no relevance to the position, such as political and religious beliefs or stories about a recent break-up.

 
Know what to expect: Expect to hear staple interview questions: "What's your biggest weakness?" "Why do you want to work here?" "Tell me about yourself." "Why did you leave your last job?" These open-ended questions are harder to answer than they sound, so think about your responses before the interview.

 
Put on a happy face: The interview is not the time to air your grievances about being wronged by a past boss. How you speak about a previous employer gives the hiring manager an idea of how you'll speak about him or her once you've moved on.

 
Unfortunately, many job seekers are not only ignoring these tips, they're making mistakes that leave unforgettable impressions for all the wrong reasons. Here are 10 real-life examples from this year's survey:

1. Candidate answered cell phone and asked the interviewer to leave her own office because it was a "private" conversation. 

2. Applicant told the interviewer he wouldn't be able to stay with the job long because he thought he might get an inheritance if his uncle died and his uncle wasn't "looking too good."
   

3. The job seeker asked the interviewer for a ride home after the interview.
   

4. The applicant smelled his armpits on the way to the interview room.
   

5. Candidate said she could not provide a writing sample because all of her writing had been for the CIA and it was "classified."
   

6. Candidate told the interviewer he was fired for beating up his last boss. 

7. When the applicant was offered food before the interview, he declined saying he didn't want to line his stomach with grease before going out drinking.
   

8. An applicant said she was a "people person" not a "numbers person" – in her interview for an accounting position.
   

9. During a phone interview the candidate flushed the toilet while talking to hiring manager.
   

10. The applicant took out a hair brush and brushed her hair.

（Author: Rosemary Haefner, vice president of human resources, CareerBuilder.com）