Upload a fresh file from the fileset you originally downloaded.
thanks,
sorry for appearing naive,but we’re a little new to all this,someone else designed our site-so where would we access our original fileset..
thanks
Well, I wouldn’t know that either would I? If you don’t have a local copy of the wp distribution, you can download the most recent version from the download link at the top of the page.
Or ask the person who did the work.
http://wordpress.org/download
You’d find the WordPress files there. If you’re missing the top-level index.php, you’ll find it in the WP zip file from that link.
If it was the index.php from your theme (located under /wp-content/themes/yourThemesName) then you’re probably going to have to contact your theme author (or look in your backups).