message confirm mail sent

Hello
When I use the little form at the bottom of home page.
once the message is sent I have a message at the top of the page displayed "your message has been sent!" - in which language file (other file or somewhere in admin )can i change the text? the screenshot is attached.
thks in advance.
Pascal

Hello,

These phrases should be available in the GK Contact system plugin language file in the administrator/language directory.

thank you very much
Pascal

I can't find these files, see attachment. Where are they specifically?

Url: http://wraysconsulting.com/

Hello,

These phrases should be available in the GK Contact system plugin language file in the administrator/language directory.

As I wrote earlier:

These phrases should be available in the GK Contact system plugin language file in the administrator/language directory.

Thanks,

I found it, its here: /administrator/language/en-GB

As I wrote earlier:

These phrases should be available in the GK Contact system plugin language file in the administrator/language directory.