Cannot turn on Web Sharing due to invalid command in .conf file

I am new to Apache. I got this error when checked Web Sharing box:

7/19/12 11:45:19.808 PM org.apache.httpd: Invalid command 'chen84/Sites/"', perhaps misspelled or defined by a module not included in the server configuration

7/19/12 11:45:19.822 PM com.apple.launchd: (org.apache.httpd[25174]) Exited with code: 1

7/19/12 11:45:19.822 PM com.apple.launchd: (org.apache.httpd) Throttling respawn: Will start in 10 seconds

7/19/12 11:45:29.855 PM org.apache.httpd: Syntax error on line 1 of /private/etc/apache2/users/chen84.conf:

.conf looks likes this:

chen84/Sites/">

Options Indexes MultiViews

AllowOverride None

Order allow,deny

Allow from all

Is this file missing something?