Site changes frm .html to .PHP

Hi

I have updated my site from abc.com/index.html to abc.com/index.php

what are the main steps i need to do so that google did not declare my content duplicate or didn't penalize.

thanks in advance

 

simply you can format hTML to Php so indexing in webmaster indexing your pages then get good results.

 

You need to 301 redirect all of the .html pages to the corresponding .php page.

http://www.google.com/support/webmasters/bin/answer.py?answer=93633