
The 'codeViewer' box will be used to display the PHP, HTML, JavaScript, etc.,
code files in HTML format. 

It will highlight the syntax of the language, if possible, by coloring
keywords, etc.

It will be able to display line numbers optionally.

It will be able to display only certain parts of the code file, if specified.

It will be able to emphasize certain lines of the code, if specified.

The 'codeViewer' box uses these state variables which modify its behaviour:

codeFile                -- code file that will be displayed
showLineNr              -- true/false   (default false)
showLines               -- 1-3;5-27     (default all the lines)
highlightLines  -- 1-3;7;13     (default none)

