Could not extend the library ?

[eluser]marcoss[/eluser]
[quote author="R@Ndy" date="1182953225"]Reply by myself...

Because my misunderstanding I used the wrong way to load the library I extend.
I should use "$this->load->library('email');" to load MY_Email class.
But I write this "$this->load->library('my_email');"
So that will pop the error message :-S[/quote]

Yup, because when you extend a core library you are actually adding extra functions to the existing one