Lots of people searching for jobs make mistakes, some big enough for them to be labeled "unhireable."

Michael Hayes with Momentum Specialized Staffing screens job applicants for companies, and he said a big part of the problem is people who don't listen.

"We have told people when they came in, `Listen, if you're going to fill out an application, you need to use a pen.' And then we had about 25 percent of the people use a pencil."

Hayes said that 25 percent got eliminated for not following directions.

Then there are those who bring drama to an interview.

"We had a couple, a man and a wife, who got into a physical altercation. The woman was battering the guy with her clipboard."

Seven out of 10 job seekers make mistakes that can lead to big setbacks, Hayes said.

Some are just horror stories.

"We'll have people who show up with their kids and let them play in the app room. We've even had people take the candies when kids were eating them and rewrap them and stick them back in the bowl."

Hayes said he's put instructions in job postings to see if job hunters would follow them -- like just show up for an interview.

"One of those instructions was, `Don't send a resume,'" Hayes said. "We had 1,500 resumes for three positions, and we probably had about 40 people come in."

Interviewing is like a sport -- practice is important, Hayes said.

"If you're playing a sport like golf, you don't just grab a set of clubs and go to the golf course. You have to practice first. Interviewing's the same thing -- facial expressions, how you sit in the chair, how you conduct yourself, looking people in the eye."

Besides not following instructions, failing to take the proper documents to an interview, is a common mistake, said Hayes.