how to slove this error after making reservation in booking moduel in joomla 2.5

Notice- You must provide at least one recipient email address.
Message - Reservation stored.

thank u it works

hi! we r planing to buy this model.. before that v are using this demo version in joomla 2.5!

i want to change texts

1. check In --> from
2. check out ---> to
and many things.

1at tried in language override but it does not supported means no change in fornt end.
2. i tried to find language ini file in language file its not found. means i not found any constant like ...

SUBJECT="Subject"
PROPERTIES="Properties"
TOTAL CAPACITY="Total capacity"
LOGIN CUSTOMER="Login customer"
LOGIN="login"
CREATE NEW CUSTOMER REGISTRATION="Create new customer registration"
REGISTER="register"
FOR MAKE RESERVATION FIRST %S OR %S="For make reservation first %s or %s"
RESERVATION TYPES="Reservation types"
TITLE="Title"
DESCRIPTION="Description"
TIME UNIT="Time unit"
GAP TIME="Gap time"
YOU ARE NO REGISTER AS CUSTOMER="You aren't customer"
BECOME CUSTOMER="Become customer"
SWITCH TO="Switch to"
BACK="Back"

please help in what file i want to change!