I have a question as:
I have a calender invitation code for gmail as below:

$vcal .= "BEGIN:VCALENDAR\r\n";
$vcal .="-//Google Inc//Google Calendar 70.9054//EN\r\n";
$vcal .= "VERSION:2.0\r\n";
$vcal .= "CALSCALE:GREGORIAN\r\n";
$vcal .= "METHOD:REQUEST\r\n";
$vcal .= "BEGIN:VEVENT\r\n";
$vcal .= "DTSTART:$dtstart\r\n";
$vcal .= "DTEND:$dtend\r\n";
$vcal .= "DTSTAMP:20110302T115742Z\r\n";
$vcal .= "ORGANIZER:mailto:$organizer\r\n";
$vcal .= "CREATED:$dtstart\r\n";
$vcal .= "DESCRIPTION:Example event 1 $desc\r\n";
$vcal .= "LAST-MODIFIED:$dtstart\r\n";
$vcal .= "LOCATION:$loc\r\n";
$vcal .= "SEQUENCE:$sequence\r\n";
$vcal .= "STATUS:CONFIRMED\r\n";
$vcal .= "SUMMARY: Example event 2  $subject\r\n";
$vcal .= "TRANSP:OPAQUE\r\n";
$vcal .= "END:VEVENT\r\n";
$vcal .= "END:VCALENDAR\r\n";

But when am using thi scode it do not show me the RSVP in mail which come as we schedule meeting from google calender.
Why so?
I checked out the calender invitation code of google calender invitataion and my invitation.
Both are same.

Then what extra section I need to add there in code?
Please help me out.

what I mean to show RSVP is as,
when google invitation comes to your (g)mail box it shows RSVP in the mail.
I want my invitation same like that.

is it possible?
or it shows only in Google to google invitation?