Adding Members to group in addressook with cocoa application

[amax]

Hello,
I want to add groups to address book. i am able to add groupName to addressbook using KABGroupName Property. but I am not able to add members to group.can any one tell me how can i add members to Newly created group ?

or I am trying to add Members to existig group also. I have implemented following code.
ABAddressBook*book = [ABAddressBook SharedAddressBook];
ABPerson *person = [[[ABPerson alloc] init] autorelease];
ABGroup *aGroup = [[[ABGroup alloc] init] autorelease];
aGRoup = [book recordForUniqueID:"here i am writting UID of that group"];

[aPerson setValue @"joy" forProperty:kABFirstNameProperty];
[aPerson setValue @"nods" forProperty:kAbLastNameProperty];

[aGroup addMember:aPerson];
[book addRecord:aGroup];
[book save];

is there anything wrong with code?
if yes ,please sggest me code for adding the members to group;
i am not getting it.

Thank You..

amax.