hello! the file is the same that for the frontend (it is a shared file)

No is not, because contains only this code.
This is only for frontend . And the backend ? Where is?


CODE of FRONTEND TRANSLATION
----------------------------------
# version 2.0.0 2010-03-20
# English Frontend Language file.
# copyright Copyright(C) 2011 JoomlaMusicSolutions.com All rights reserved - Todos los derechos reservados.
# Translation: www.joomlafinances.com
# Todos los archivos ini deben ser guardados como UTF-8 sin BOM - All ini files must be saved as UTF-8 NO BOM


TOTAL=SKUPAJ
FROM=OD
TO=Za
FILTER_RESULTS=Filter
SUBTOTAL=Subtotal
INVOICE_DATE=Datum računa
INVOICE_NUM=Številka računa
TO_NAME=To

ERROR_SENDING_INVOICE=Error sending invoice $s to %s
INVOICE_SENT=Invoice %s sent to %s

VIEW_INVOICE_ONLINE=Poglej račun online
SEND_EMAIL=Pošlji račun po mailu
VIEW_INVOICE_DETAILS=Poglej podrobnosti

NOT_AUTHORIZED_INVOICE=You are not authorized to view this invoice
NOT_ALLOWED_SEND=You are note allowed to send this invoice

PAYED=Plačano
PENDING=Ni plačano
CREATE_INVOICE_FOR_CONTACT=Ustvari račun za ta kontakt
CLICK_TO_EDIT_EDITOR=Urejaj grafično
CLICK_TO_EDIT=Urejaj tekstovno
NO_INVOICES_AVAILABLE=There are no available invoices to show
INVOICES_TITLE=Moj račun

hello! but.. this does NOT load on the backend as well?
the file is the same... (I know it says "English Frontend Language file" but it's for both...)

do the sentences in the backend DONT get translated?

The complete traslation english file for backend and frontent is here:
components/language/en-GB/en-GB.com_invoices.ini

.... IS THIS TRUE?

--------------------------------------------------------

not really, it's here:

/language/en-GB/en-GB.com_invoices.ini

(not in /components)

OK. This my file contain this code:
---------------------------------------

TOTAL=Total
FROM=From
TO=To
FILTER_RESULTS=Filter results
SUBTOTAL=Subtotal
INVOICE_DATE=Invoice date
INVOICE_NUM=Invoice num
TO_NAME=To

ERROR_SENDING_INVOICE=Error sending invoice $s to %s
INVOICE_SENT=Invoice %s sent to %s

VIEW_INVOICE_ONLINE=View invoice online
SEND_EMAIL=Send invoice to email
VIEW_INVOICE_DETAILS=View invoice details

NOT_AUTHORIZED_INVOICE=You are not authorized to view this invoice
NOT_ALLOWED_SEND=You are note allowed to send this invoice

PAYED=Payed
PENDING=Pending
CREATE_INVOICE_FOR_CONTACT=Create invoice for this contact
CLICK_TO_EDIT_EDITOR=Click to edit using WYSIWYG editor
CLICK_TO_EDIT=Click to edit using plain text

NO_INVOICES_AVAILABLE=There are no available invoices to show
INVOICES_TITLE=My invoices
---------------------------------------

But this is not enought for backend translation.
PLEASE send me yor ENGLISH TRANSLATION.

this is exactly the same file we are using...!

tell me: what is missing? you say it's not enough for backend translation... what sentences are missing?

Nothing missing in English,
I simply must translate English beckend in Slovenian beckend.

How can I do this?

I need more code for translate other backend words.

Exaple words : Invoice num Recipient name Company E-mail Linked to contact Linked to Joomla user Invoice date


Where are this beckend words???

hmm these words are not on the file, you are right.
but you can ADD them yourself and they will be translated.

just do this:

INVOICE NUM=Your translation

etc. and it will appear

Yes I know this.

But I need the CODE of other words.


Example:
INVOICE_NUM=my translation
INVOICE_DATE=my translation
...


Send me the code, please. Or more instructions where are other english words to translate. Some words I find in en-GB.ini file.

no, there is no "code", you just have to set the words EXACTLY how you see them, but in uppercase.

so

INVOICE NUM=my translation

(not INVOICE_NUM=my translation, not underscore in this case)
do you know what I mean?

INVOICE NUM=my translation .
YES! Works. It' OK!

Now I have only one problem. About MAIL SENDIND INVOICE.
---------------------------------------
THIS IS THE ERROR MESSAGE, WHEN I TRY TO SEND MAIL-INVOICE in BECKEND ADMIN:
Could not instantiate mail function.

Joomla version: 1.5.26
com_invoices_1.0.0.zip

Rgrds.