What is the step to sell it to a major software corporation such as
MS, etc? Do I need to copywrite or pattent?

Certainly a copyright (on code that you have written) is easier to
obtain than a patent.  Software patents, while not exactly
commonplace, are no longer the novelty they were 20 years ago.  But
the process of patent application is lengthy and expensive, requiring
the services of a patent attorney.

Strictly speaking you have a copyright in the code you have written
independent of registering the copyright.  However if you believe your
code is of commercial value and plan to market (sell) the application,
it would be a responsible choice to register the copyright.  I believe
the copyright application process has been covered in other Answers at
this site, but if you wish, I could point you to links that cover the
requirements (fees, copies of original work, etc.).

regards, mathtalk-ga

May be you should contact Yahoo 
Groups.Yahoo.com/groups/Projects_and_Ideas

They might offer you  a sales and marketing deal

Thanks. Please point me out to the right links.

Thank you