Editor's Note: This is a recap of a program that was orginally broadcast on Good Friday, April 14.

Shares of Crystallex ( KRY), which operates the biggest gold mine on Earth, have more than doubled since the year began, Jim Cramer said on his "RealMoney" radio show Friday.

But Cramer said he wants use Crystallex to teach people a very important lesson regarding the time frame of stocks. Market players should buy weakness and sell strength, he said. Although people always talk about buying low and selling high, they like to buy high and hope the stock goes higher.

But they need to think about the time frame. When you do your homework and think of going into a company, take advantage of market fluctuations, he said.

"When stocks are sliding, you should be interested in buying, and when they are soaring, you should be interested in selling," Cramer said. "It's about facts and doing it right, increasing the odds and making money."

An approach that might make you money is looking six to 18 months ahead of when you buy a stock, he said. By nature, Cramer said, he is impatient and wants to make money now.

He said he's been talking about Crystallex for weeks, and has even talked with the company's CEO.

If people decided to get into the company, they might have bought it around $6, and then it went down to $5. Now, some people might be worried about the price slide, he said, adding he knows this because many people wrote to him asking what was going on with the company one day after it started dropping.

I know no one likes to lose money, but during price fluctuations nothing has changed with the company. Since April 14, the stock has fallen to $2.87 .

Cramer said he believes people should buy Crystallex while it's coming down because essentially it is a huge gold mine with gold 18 inches below the surface.

After the company gets that 18 inches of soil off the ground, can you imagine how much money you're going to make with gold at $600 an ounce? he asked.

Patience, time frame, making sure nothing has changed with the company or its regulations, are all ways that might lead to people making money, he said.

Inside Threat

When people hear about insider trading, the movie Wall Street usually comes to mind, Jim Cramer said on his "RealMoney" radio show Friday.

Insider trading has reared its head once more as analysts from Merrill Lynch ( MER)and Goldman Sachs ( GS) were recently arrested and charged with insider trading and securities fraud. But Cramer said he has no sympathy for them.

While the Securities and Exchange Commission used to rely on whistle-blowers for tips, now the SEC process used to catch insider trading has become more sophisticated as they have the ability to track every trade.

"They will nail you" if you are caught, he said, adding to remember that in the case you are caught, you are presumed guilty until proved innocent.

If you get a tip, look at both sides of what it is, he said. If you get insider information and gain from it, the government will come and confiscate your gains at best and throw you in jail at worst, he said.

If everyone knows the tip you're not going to profit from it, he added.

"Tips are for waiters, and will cause you to lose money," he said, adding that if people are buying stocks on tips they don't need to listen to Cramer's show because they won't have money to play the game.

Zoltek ( ZOLT) has moved from $9 to $21 and now it's time to sell it, Cramer said.

Instead, he recommended getting into Chesapeake Energy ( CHK), since he believes natural gas prices are going to rise. In recent Friday trading, Zoltek was at $24.23, while Chesapeake was at $29.35.

Touting Titanium

Titanium Metals ( TIE) makes the increasingly popular titanium that goes into aircraft, Cramer told a caller.

Boeing ( BA)and Airbus have been buying all the titanium. While Titanium Metals was at $8 one year ago, it's now at $53, he said. The stock was recently at $25; the company effectuated a 2-for-1 stock split on May 16.

Cramer said he is reluctant to tell people to sell it because of news that the company's chairman just bought 50,000 shares, he said. That tells him the stock's not done going up, he said.

The chairman is buying, Boeing is buying, Airbus is buying and you should be buying, he said.

Cramer said Johnson & Johnson ( JNJ) is a company he has looked at for greater growth. It is a company that is generally a wealth creator and has its act together, but it has been acting horribly, he said.

It can't seem to get out of its own way, he said, adding that it has been competing with Amgen ( AMGN) and losing.

He believes Procter & Gamble ( PG) has better growth prospects, and recommended buying Procter & Gamble and holding Johnson & Johnson.

Martek Biosciences ( MATK), which makes micro algae products and helps in drug discovery, has been falling like many of the healthcare companies out there, Cramer told a caller.

However, he said he has heard of a couple of huge contracts coming for the company, so he said he wouldn't give up on it, but at the same time he wants people to understand that the healthcare has been down, as has Martek.

GameStop ( GME) is a best-of-breed place to buy video games, he said when a caller asked about it.

It's been en fuego since the Xbox 360 came out. Cramer said he would wait till it goes down $43 or $44 and then buy more. On Friday, the stock was at $39.17 .

"It is going to have a dynamite 2006," he said.

Here's your chance to pick the stock you'd like me to feature on my radio show July 20:
Forest Labs

REMEMBER to listen in on Thursday for my take on the stock that wins this poll!

Jim Cramer is a director and co-founder of TheStreet.com. He contributes daily market commentary for TheStreet.com's sites and serves as an adviser to the company's CEO. Outside contributing columnists for TheStreet.com and RealMoney.com, including Cramer, may, from time to time, write about stocks in which they have a position. In such cases, appropriate disclosure is made. To see his personal portfolio and find out what trades Cramer will make before he makes them, sign up for Action Alerts PLUS. Listen to Cramer's RealMoney Radio show on your computer; just click here. Watch Cramer on "Mad Money" at 6 p.m. ET weeknights on CNBC. Click here to order Cramer's latest book, "Real Money: Sane Investing in an Insane World," click here to get his second book, "You Got Screwed!" and click here to order Cramer's autobiography, "Confessions of a Street Addict." While he cannot provide personalized investment advice or recommendations, he invites you to send comments on his column by clicking here.

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