NEW YORK ( MainStreet) — When a co-worker asks you out and it's not something you feel comfortable with, it's not always easy to refuse politely. If you're too harsh, you could risk making them angry or upset, but if you're too friendly, you could end up leading them on. It's no secret that dating in the workplace can jeopardize your career, but working with someone you've turned down can also create unnecessary negativity and tension at the office. We checked in with experts who weigh in on the five best ways to decline a date with a colleague and still keep things positive at the water cooler.

1. Thank them — let them know you're flattered.

You want to thank the person, even if you're uncomfortable, says Dana Corey, founder of relationship coaching firm Modern Relationship Expert in Portland, Ore.

"Even if you have no intention of ever going out with this person, you have to thank them," she says. "They think enough of you to ask you, and that's worth showing a little appreciation."

Thanking the person also helps prevent them from feeling rejected or upset, Corey says, adding that it's important to keep in mind how you want the person to feel about you when you leave the conversation.

"They need to walk away feeling like they were respected, that you heard them," she says. "When you thank them for their offer, suddenly they feel like you had a real conversation — not that they were just brushed off."

Also, remember that by the time someone asks you out, they've probably been admiring you from afar from a while, and it takes courage to speak up, Corey says.

"Asking you out was not something they did lightly. They had to build up their nerve to do this, and at the very least you need to tell them you appreciate their offer," she explains.

2. Let them know of your career concerns.

Examine your employee handbook for details on your company's dating policy, says Jennette Pokorny, vice president of marketing and communications at EverNext HR . Most companies have rules against a manager and a subordinate dating, and other policies that may make your conversation easier.

"It's great to be able to say, 'I really value my career, and unfortunately our company really frowns on dating, and so I've made it a policy not to go out with anyone in the workplace,'" Pokorny says.

Using this tactic will make the other person feel like you aren't rejecting them — you're just following company procedure, she says.

"It definitely saves face to put it off on the company and let them know that dating just isn't the right move for either of your careers."