Hey i didnt see the episode a really long time ago when someone came out of the closet. Would someone please fill me in?

You're thinking of the Gay Witch Hunt (Season 3, Episode 1), when Oscar is outed by Michael. :)

Here's the plot summary from Wikipedia:

After calling Oscar Martinez (Oscar Nunez) "faggy", Michael Scott (Steve Carell) learns that Oscar finds the word offensive because he is homosexual. Michael inadvertently outs Oscar to the entire office. Jan Levinson (Melora Hardin) berates Michael for his behavior, after Michael's seminar on homosexuality is a disaster. When Oscar threatens to quit, Michael attempts to reconcile with Oscar, first by hugging him, and then kissing him on the lips. Oscar is given three months paid vacation and use of a company car in exchange for not suing Dunder Mifflin.

It is revealed that after their kiss, Pam Beesly (Jenna Fischer) confirmed to Jim Halpert (John Krasinski) her intention to marry Roy Anderson (David Denman). However, a few days before the wedding, Pam got cold feet and decided to call it off. She moved into her own apartment and began taking art classes. Pam's rejection sent Roy into a downward spiral, hitting rock bottom with a drunk driving arrest. When being interviewed by the camera crew, Roy makes a vow to win Pam back.

Jim has transferred to Dunder Mifflin's Stamford branch and settles into his new office. He befriends smug co-worker Andy Bernard (Ed Helms) who brags about his wild college days at Cornell University. Meanwhile, sales representative Karen Filippelli (Rashida Jones) expresses disdain for Jim's constant smirks to the camera.

Haha, buying gaydar online!! The kiss scene is so unpleasant...

its Oscar.

yes

gay witch hunt! haha hilarious episode! pretty much michael makes a joke to oscar calling him a fag. and oscar takes it seriously and tells toby. toby talks to michael. and michael doesnt believe him. angela doesnt really talk to oscar that much. dwight and michael call jim at the stamford branch to find out where gaydar is. its a radar that detects gay people. cause they wanna know who else is gay in the office. michael holds a conference where he talks about the situation. oscar OFFICIALLY comes out to everyone. michael talks about oscar in the rainbow parade. michael tries to kiss oscar. thats the frame down below. and finally in the end. michael sees gill pick up oscar. and michael says i wonder if he knows oscar is gay. but gill and oscar and datin :) oscar gets a paid vacation and dwight receives the gaydar but it says that hes gay! hilarious episode!