> I have read the manual "An Introduction to Programming in Emacs Lisp".
> But still I can not be able to write complete code of lisp .
I use emacs for like 8 hours a day daily since 1998. I read quite a lot emacs manual. For the first about 5 years i use emacs completely in a text terminal with emacs keybinding and ways. I thought i knew a lot about emacs, yet i didn't know shit about elisp until 2006 i started to learn it. Kinda resisted learning it. Learning a bit elisp helps your emacs using a lot. I've been programing elisp in a leisurely since 2006, am pretty good for using elisp as a text processing lang such as perl, python, but still quite hard to code emacs features such as major mode, minor mode, frames/windows, font etc.
just patience and practice. If you are not a programer, more practice i guess.
I have now some emacs tutorial i think you probably have seen. Here's some simple examples that might help.
• Emacs Lisp Examples
start small and gradual works well for me.