This is my first time using the support forum, so I hope I'm following the correct protocol.
I wanted to make the posts on my homepage appear as excerpts with thumbnail images, so I followed the advice here: http://zeaks.org/tutorials/show-excerpts-and-post-thumbnail-twenty-eleven-theme/.
I'm always reading how you should never edit the parent theme, so I copied the functions.php and content.php files to my child theme directory. There, I changed the code as per Zeaks' instructions and uploaded the files to the server.
When I went to my blog, http://www.skiedesign.net/blog, I got a white screen of death. The same thing happened when I tried to access my admin panel.
To undo whatever I had done, I promptly deleted the functions.php and content.php files that I had added to my child theme directory. But my site and admin panel still do not load.
I then completely removed my child theme directory, to no avail.
Finally, I downloaded a new version of Twenty Eleven to replace my old (possibly corrupted) one. Even though everything should now be in its virgin state, my site and admin panel still do not load.
Any ideas? I don't read or write php, and I was nervous about monkeying with those files. I've since read that I should not have copied functions.php to my child theme directory, but I hope the error will not be fatal.
Many thanks in advance for your assistance.