These are questions you can easily find the answer to in a search engine and on the PHP.NET website.
If you have a legitimate question, by all means ask it but please stop filling the forum up with pointless posts.
First: define what you mean by "error reporting." There is error-logging which is essentially always on, and you just need to determine where the logs are. There are also settings and commands that control if/what gets displayed when there is an error (or warning or notice) (search for display_errors and error_reporting).
No point in asking NogDog, I deleted several posts just like this by this person who after 4 or 5 like these comments and threads ended up with being booted off for a while.