Used to trigger a user error condition, it can be used by in conjunction
with the built-in error handler, or with a user defined function that has
been set as the new error handler
(set_error_handler()).
This function is useful when you need to generate a particular response to
an exception at runtime.
Parameters
error_msg
The designated error message for this error. It's limited to 1024
characters in length. Any additional characters beyond 1024 will be
truncated.
error_type
The designated error type for this error. It only works with the E_USER
family of constants, and will default to E_USER_NOTICE.
Return Values
This function returns FALSE if wrong error_type
is
specified, TRUE otherwise.