How do invite contact with my Calendar

Hello everyone :

I have :

Iphone 4 with the last iOs version.

A google account linked to my Mail / Calendar.

My Problem :

When I create a new event with my iPhone i do not have the invitee button.

When I create an event with Google Calendar and I invite a contact, i can not modify the event through iCal with my Iphone (The modify button (on the right top) does not exist ...)

Is that Normal ? It seems that the invitee button did exist in the previous iOS version.

Thank you in advance.

Regards,

Adrien