Can you recognize online fraud when you see it? Here's a quick guide to the top scams and schemes you're most likely to find on the Internet.

1. Overpayment Scam

The setup: You purchase a large ticket item such as a car and are "mistakenly" asked for too much money. The seller then asks you to return the overpayment amount via wire transfer, normally to the tune of several thousand dollars.

What actually happens: You pay for the item but never receive it, and send the "overpayment" back to the seller. The seller then closes the account, making him or her impossible to track.

The risk: Serious financial loss. You have no car and no money.

The question you should ask: Don't these people know the price of their own products?

2. Auction Fraud

The setup: Online auction fraud accounts for three-quarters of all complaints registered with the FBI's Internet Crime Complaint Center. The most common one is where you send in your money and get nothing but grief in return.

What actually happens: You never get the product promised, or the promises don't match the product. The descriptions may be vague, incomplete, or completely fake.

The risk: You lose time and money. If you report the scam, the seller may retaliate by posting negative eBay reports about you using phony names.

The question you should ask: Who would sell a $200 bag for $20?

3. Phishing Scams

The setup: You receive an e-mail that looks like it came from your credit union or other institution, warning you about identity theft and asking that you log in and verify your account information. The message says that if you don't take action immediately, your account will be terminated.

What actually happens: Even though the e-mail looks real, complete with authentic logos and working Web links, it's a fake. The Web site where you're told to enter your account information is also bogus. In some instances, really smart phishers direct you to the genuine Web site, then pop up a window over the site that captures your personal information.

The risk: Your account information will be sold to criminals, who'll use it to ruin your credit and drain your account.

The question you should ask: If this matter is so urgent, why isn't my credit union calling me instead of sending e-mail?

NOTE: A recent Phishing e-mail scam was reported on April 25, 2005. This Phishing e-mail was sent to both the general public and to some credit unions' members. It appeared to be from the NCUA (National Credit Union Administration). This false e-mail asked for the recipient to click on a link to verify their account registration. If the recipient proceeded to do so, the link directed them to a false web site and asked for their Credit Union account number and PIN.

NCUA was alerted to this scam on April 23, 2005 and the web site was shut down. However, you should be aware that these types of fraudulent schemes have a habit of reappearing in a same or similar fashion.

For more information, including how you can report this crime, go to www.cybercrime.gov

4. Nigerian 419 Letter

The setup: You receive an e-mail, usually written in screaming capital letters, that starts out like this:

"DEAR SIR/MADAM: I REPRESENT THE RECENTLY DEPOSED MINISTER OF AGRICULTURE FOR NODAMBIZIA, WHO HAS EMBEZZLED 30 MILLION DOLLARS FROM HIS STARVING COUNTRYMEN AND NOW NEEDS TO GET IT OUT OF THE COUNTRY..."

The letter says the scammers are seeking an accomplice who will transfer the funds into their account for a cut of the total--usually around 30 percent. You'll be asked to travel overseas to meet with the scammers and complete the necessary paperwork. But before the transaction can be finalized, you must pay thousands of dollars in "taxes," "attorney costs," "bribes," or other advance fees.

What actually happens: There's no minister and no money--except for the money you put up in advance. Victims who travel overseas may find themselves physically threatened and not allowed to leave until they cough up the cash.

The risk: Serious financial loss--or worse. Victims of Nigerian letter fraud lose $3,000 on average, according to the FBI. Several victims have been killed or gone missing while chasing a 419 scheme.

The question you should ask: Of all the people in the world, why would a corrupt African bureaucrat pick me to be his accomplice?

5. Postal Forwarding/Reshipping Scam

The setup: You answer an online ad looking for a "correspondence manager." An offshore corporation that lacks a U.S. address or bank account needs someone to take goods sent to their address and reship them overseas. You may also be asked to accept wire transfers into your bank account, then transfer the money to your new boss's account. In each case, you collect a percentage of the goods or amount transferred.

What actually happens: Products are purchased online using stolen credit cards--often with identities that have been purloined by phishers--and shipped to your address. You then reship them to the thieves, who will fence them overseas. Or you're transferring stolen funds from one account to another to obscure the money trail.

The risk: After a few months, your credit union account will be cleaned out. Worse, when the feds come looking for the scammers, you're the one they're going to nail.

The question you should ask: Why can't these people receive their own darn mail?

6. "Congratulations, You've Won an Xbox (news - web sites) (IPod, plasma TV, etc.)"

The setup: You get an e-mail telling you that you've won something cool -- usually the latest hot gadget, such as an Xbox or an IPod. All you need to do is visit a Web site and provide your debit card number and PIN to cover "shipping and handling" costs.

What actually happens: The item never arrives. A few months later, mystery charges start showing up on your credit union account. The only thing that gets shipped and handled is your identity. (A more benign variation on this scam drives you to a site where you're asked to provide your contact info and agree to receive spam from advertisers until unwanted e-mail is coming out of your ears.)

The risk: Identity theft, as well as lost money if you don't dispute the charges.

The question you should ask: When did I enter a contest to win an Xbox (iPod, plasma TV, etc.)?