char driver error

[Aravind Vijayan]

Hi all,
       Let me begin this post with thanx all to whom help me on
previous problem.I have completed jobs such as
writing,making,inserting the  module.

i create a character special file using mknod in /dev directory.

i try to write data to my file by" echo -n "abcd" > /dev/memory "

and when i try to read from that file i get  the last char was written
to that file that is "d"

here is my code:http://pastebin.com/9YsJetek