Reason why we will use PHP random functions and not javascript ones is mainly based on these languages' nature.
JavaScript is interpreted by the web browser as the page is viewed. First of all, browsers do not behave the same way especially when handling javascript. Search engine spiders act like primitive browsers and often ignore javascript.
Furthermore, since randomic algorithms demand a sort of calculation before the final output, this 'funny' situation would occur:

Effective, unpredictable, random elements should not be chosen by the browser. This because browser knows all available options and randomly choose one. After this process one of the options is displayed on web page.

What we want to achieve is a process which is randomic for both the browser and the webpage viewer.
PHP is an open source programming language used for creating server side applications. A web page written in php is first interpreted by the server, then feeded to the browser in a static, plain html, form. Unless you enhance a php page with weird javascripts, there won't be any compatibility problems
That's a crucial fact: a random function written in Php is interpreted BEFORE browser display the page: the browser and the human viewer watch the SAME page.

The latest hype about search engine optimization involve randomization. As always, we ensure there's NOT a unique, sure, method to achieve high and stable rankings. Don't trust who claim to have discovered the 'secret' of random functions as a golden road to # 1 position. That's NOT true.

By the way, use of random elements within a webpage can help a lot for:

• Doorway pages technique: having some embedded random elements within the pages, help preventing "duplicated pages penalization" (or too similar ones) and doorway page penalization. This because pages are unique and appear to be frequently updated (or, at least look different when spiders index them).
• Stale-Page prevention: even 'honest' pages may be penalized when spiders see a lack in updating them. Adding some PHP random elements those pages will always look 'fresh'.
• Great Benefits in having often updated webpages. Even if they're not really updated, that's what spiders will assume when they'll index and cache a page which is always different.

As a matter of fact, randomization, while NOT being the ONLY and BEST way to achieve high rankings, is a great technique to prevent some of those negative factors that could penalize your website. And we think it deserves at least a try.

Next chapter we will explain some basic PHP scripting and how to embed PHP script into webpages. This section is designed for newbies and for those who are -for any reason- scared of programming language. Those who are familiar with Php issues can jump to Main PHP Random Tools page