Maybe I should make my reply more complete. Remember that options will settle over the weekend. The actual trades of stock, etc. in your account to complete the trades will occur on Monday morning after the market opens. If you haven't closed your position on Friday, you can really be hurt if my example of Priceline would gap down 15 points over the weekend because of bad news. Best advice for new guys is to call your broker especially the big firms. They have brokers on staff that all they do is spend Fridays (and other days) fielding calls (and making calls) to help people with trades gone bad. That is what your commissions are paying for. So swallow your pride and call. If you miss Friday, then call Saturday morning all the way to Monday morning till you get through to talk to them. Besides it helps you establish a relationship with your broker and you are letting them know you are staying on top of your account. Most send warning emails about expiring positions that are near or in the money and that they may step in. If they think you are a trader not paying attention to your account, they may step in and execute a trade you don't like on Friday. Even if you don't need advice, it doesn't hurt to make a quick call to their 800 number to let them know you are watching the account and following the market and prepared to take action on a trade such as close it, or close it and open a new position in a later period (a roll), or whatever. They can cut you off from trading the whole account if they think you aren't acting responsibly.
Thanks so much. My broker is IB and I donot think IB will be good if I call them . IB has some instruction which I can give for option exercises on line.