Where should the GWO control script be placed

[latha]

A/B Test

In GWO , we have a little piece of code, known as the control code. This code goes at the very top of the A page.

What is the purpose of the control?
When a visitor requests test pages, some visitors are sent to the A version of the page and some to B. The control script decides where they should go.

The control page should be added to the top of the page and after the Doc Type Declaration and before content. Do you know why?
Here is a very informative article by Eric Vasilik ->http://www.gwotricks.com/2009/02/where-does-control-script-belong.html