I am pretty new to all this web development stuff and I have a site that I would like to expand with a few extra features that are built into Apache, but the configuration file, located at /etc/httpd/httpd.conf, is being a b*tch. I am trying to turn on SSI but when I try to save the config file after the proper changes there's an error message that comes up that says "[ Cannot open file for writing ]". I am using PICO to edit the file. What am I doing wrong?