How to Write hidden code

Recently, many Webmasters have been discussing topics such as black chain, and software. Black chain is not needed, and you will not be able to leave it after it is used, there are many people who say that he has some disadvantages, but there are a lot of people who can't really say that he can't get the black chain. In fact, there is no benefit to the Black chain. I will know if I use it myself, because I have done it myself, the following describes several common e-commerce methods. By the way, you can often check whether your website has been infected with a Trojan horse. If yes, clear it in time.
Div: Class
<Div style = "display: none;">
<A href = http://www.seorv.com/
Target = "_ blank"> website keywords </a> </div>
Javascript: Class
<Script language = "JavaScript" type = "text/JavaScript">
Document. Write ("<Div style = 'display: none; '> ");
</SCRIPT> <div>
<A href = http://www.suuhuu.com/> website keywords </a>
<Script language = "JavaScript" type = "text/JavaScript">
Document. Write ("</div> ");
</SCRIPT>
HTML: Class
<Marquee Height = 1 width = 5 scrollamount = 3000 scrolldelay = 20000>
<A href = http://www.51breast.com> website keywords </a>
</Marquee>
Css1: Class
<Div style = "position: absolute; top:-999px; left:-999px;">
<A href = http://www.seorv.com/> keywords </a>
</Div>
Css2: Class
<Div style = "position: absolute; left: expression (1-900); top: expression (3-999);">
<A href = http://www.371anmo.com/> keywords </a>
</Div>
I hope you can only learn the methods, but you must also have ethics. You must not use them in disorder. You must use the harmony of the Internet. If you engage him in your affairs, why, it's better to honestly do the content of the traffic! This is not a long term, and the clever method is also short-lived, because sometimes the search engine will drop you K. We recommend that you be a real friend of the station. Do not use a black chain. The black chain is short-lived. If you come up with a long black chain, once you are found, your website is basically useless.