Technical Details


As a rule the pages are coded in accordance with the XHTML-1.0-Standard. More extensive documents are presented in the PDF format. Illustrations are usually presented in the GIF or in the case of photographies in the JPEG format. Outline drawings and plans are offered in the SVG format in the frame of the possibilities.

In the case of older browsers e.g. Netscape 3.0 the output of the XML declarations, which are actually located in the not printable document head, can still occur.

Site navigation bars, which based on the <link> tags, are supported.

Pop-up windows

Under certain circumstances so-called Pop-up windows are used for explanations. Their window name is “Abbr”.


The Unicode character set is used for coding almost all pages to clearly code all characters (letters and numbers) on this site. This character set is supported by all modern operating systems and by all browsers of the 4th generation.

The “Arial Unicode MS” character set used here is a component of the Microsoft ® Office-2000 and Office XP packages.

The special characters Hamza and ʿAin used for the transliteration for instance of Arabic texts are coded as follows:

Hamza ʾ U+02BE Modifier letter right half ring
ʿAin ʿ U+02BF Modifier letter left half ring

Style Sheets

The page layout is defined by following style sheets:

Information area: main.css, main-base.css, main-advanced.css, main-layout.css, main-print.css, main-aural.css.

JavaScript programmes

Almost all code sequences are united in only one external file: main.js. With few exceptions, the Javascript code was not written directly into the HTML document. Important comments are written in the HTML files.

It was tried by using pre-checks that no error messages are presented due to missing functions or objects – also in the case of older browsers.


The names of the four Cookie variables used on this site are: popUp, selectedStyle, duration and refreshed. The values of these variables can be seen and controlled by you by using the Cookie manager of your browser. A fifth Cookie variable named testIt is used to determine whether the acceptance of Cookies is permitted; however this Cookie will be deleted immediately after the check.

For the popUp cookie, the value 1 means enabled option, the value 2 means disabled option. The selectedStyle cookie designates the number of the used style sheet: 1: Default style sheet, 2: old sytle sheet, 3: first alternative, 4: second alternative style sheet. duration indicates the duration of the storage in days of the cookies mentioned. The cookie variable refreshed is used to re-set the cookie variables mentioned in the course of at least one day. Thus the period of the storage of the cookie variables is re-set to the entire given period again by the visit of the homepage, however after one day at the earliest: It will be checked whether in the last 24 hours already a re-setting tooks place by using the cookie variable refreshed, which is stored only one day.

Internet Workshop

Manuscripts and exercises of my lecture “Internet Wokshop” (in German) are part of this site.