Trouble with Leave a Reply Comments Form

Greetings: I am using the Twenty Tem 1.2 theme for WordPress and was having problems with the “Leave a Reply” box showing up on pages but not on my first post. I foolishly went into the Appearance, and then Editor, Comments and tried a fix I found on the internet. It did not work and generated more problems. Now the pages on my website show the following error next at the end of the page:
Parse error: syntax error, unexpected ‘;’ in /home/thrive11/public_html/wp-content/themes/twentyten/comments.php on line 77
Also, there is still no “Leave A Reply” box on the home page where I put posts.
Can anyone tell me how to fix this so that I get a “Leave A Reply Box on both the pages and the posts? Thanks.