how do i set the index file in apache to a .php file ? when i goto localhost it just says access denied but when i goto localhost/index.php it works... is it part of php.ini or httpd.conf?

In your httpd.conf file you should have this section. If not then put it in.

# DirectoryIndex: Name of the file or files to use as a pre-written HTML
# directory index. Separate multiple entries with spaces.
#
<IfModule mod_dir.c>
DirectoryIndex index.html index.htm index.php index.php3
</IfModule>

And when you make any changes make sure you restart Apache.