You might have a web page which is of interest to the user. You might have a button (or link) around the top of the page which would allow the user to do some temporary processing before coming back to the page. For example, clicking the button might require that the user gives details to let him sign in, or choose certain options that will enable the server to create a web page catering to his interests. This two-part article series will show you how to get it done.
After clicking the button, some web pages shift the part of the page below the button downward, giving room for a pane that contains the requirements of the details you have to act on (for example, sign in). It is possible for the web designer to develop a window panel that will go in front of the top area of the page without shifting anything downward. When you finish giving the details or acting on the panel, you close the panel. I prefer this approach to the former. I show you how to do this in this article series.
You can download the zip file, unzip it, open the files in your web browser, and click the Process Info button to have a feel about the phenomenon before you continue to read the article (many of the files have a button called the Process Info button).
The web page and XHTML
I use XHTML norms for the design. The basic XHTML page in our project is:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">