API AcceptGroup

Accepts the invitation from a group.
 AcceptGroup()
==Example==
The following snippet auto-accepts invitations from characters whose names begin with the letter A.
local frame = CreateFrame("FRAME")
frame:RegisterEvent("PARTY_INVITE_REQUEST")
frame:SetScript("OnEvent", function(self, event, sender)
	if sender:sub(1,1) == "A" then
	 AcceptGroup()
	end
end)
==Details== 
*You can use this after recieving the event. If there is no invitation to a party, this function doesn't do anything.
*Calling this function does NOT cause the "accept/decline dialog" to go away. Use ("PARTY_INVITE") to hide the dialog.
*:Depending on the order events are dispatched in, your event handler may run before UIParent's, and therefore attempt to hide the dialog before it is shown. Delaying the attempt to hide the popup until resolves this.