How to set error-log-monitor plugin

Dear Sir,

Home page is broken,I want to know why?
So want to install the plugin.
http://digwp.com/2009/07/monitor-php-errors-wordpress/
http://wordpress.org/plugins/error-log-monitor/installation/

Step 1: Create a log file

Create an empty file called “php-errors.log”. This file will serve as your site’s PHP error log. Your server will need write access to this file, so make sure to set the appropriate permissions. This file may be placed in any directory, but placing it above the web-accessible root directory of your site is advisable for security reasons. Once this file is created, writable, and in place, take note of its absolute directory path and continue to the final step.

Question 1.
Can I add file “php-errors.log”. to
/public_html
php-errors.log

or to
/public_html/wp-content

or just go
/

same as /public_html

where should be?

Step 2: Add the magic code
Next, open your site’s wp-config.php file (located in the root WordPress directory) and place the following code immediately above the line that says, “That's all, stop editing! Happy blogging.”:

Once in place, edit the third line with the absolute directory path to the php-errors.log file created in the first step. Upload to your server and call it done. All PHP errors will now be logged to your php-errors.log file, thereby enabling you to monitor and resolve errors as quickly as possible.

// log php errors
@ini_set('log_errors','On'); // enable or disable php error logging (use 'On' or 'Off')
@ini_set('display_errors','Off'); // enable or disable public display of errors (use 'On' or 'Off')
@ini_set('error_log','/home/path/logs/php-errors.log'); // path to server-writable log file

Question 2 How to edit the third line?

edit the third line with the absolute directory path to the php-errors.log file created in the first step

If I use this how to edit the third line?
Can I add file “php-errors.log”. to
/public_html
php-errors.log

Thanks!