PHP files editor

By which software i can edit my PHP files online. Or i need to do this offline.

I need to make my site search engine compatible but it has PHP page as index file. so please guide me. As i can do front page editing work with html pages.

php pages are perfectly SE friendly, its the html code that they spit out that matters. The SE sees no code from the script as that os all parsed server side. What exactly are you trying to do?

I need to enter keywords, tags and to make other editing work in my php site.

add these to the html of the php. If you dont know php or if it isnt set up using smarty or templates than you will have a very difficult time editing the php. You have to look at how to create the new variables with your code and I know of no GUI which allows this except smarty, which only works if the site ws built with smarty in the get go.

I need to know where i can open php files for editing rest i will manage.

any text editor, even notepad will work.

I use Dreamweaver, or ultra edit both of which color the code so that its easier to read. Note pad being black and white is much harder to read, so i use "programmers notepad" sometimes also. Download them here:
Programmers notepad (free)

Ultraedit (my favorite)

I think ultraedit works better.....can u refer me free link site to get this

Ultra edit costs money. It has a free trial on their site. Of course you could check the torrents but I wouldnt know of a link for those...