Uing these code, i could not get info. from contactdatabase. Why?

I have insert 6 item (each item include "KUidContactFieldGivenName, KUidContactFieldFamilyName, KUidContactFieldPhoneNumber")into contactdatabase, but i can not read from it, Why?

i am appricated to Anyone who answer this tiny question!!!!!!

=========================================================================================
CminiAccessContactDB::CminiAccessContactDB()
{
iDB = CContactDatabase::OpenL();
CleanupStack::PushL(iDB);
}

. . .

void CminiAccessContactDB::EditItem()
{
CContactItem* card = NULL;
TInt iCnt = iDB->CountL(); //correct! Get 6 items

for(TInt i(0); i < iCnt; ++i)
{
card = iDB->ReadContactL(i);
CleanupStack::PushL(card);
CContactItemFieldSet &fields = card->CardFields();
TInt fieldCnt = card->CardFields().Count();

TInt posGivenName = fields.FindNext(KUidContactFieldGivenName);
if(KErrNotFound != posGivenName)
{
TPtrC givenName = fields[posGivenName].TextStorage()->Text(); // pointer is NULL , ??????
}

TInt posFamilyName = fields.FindNext(KUidContactFieldFamilyName);
if(KErrNotFound != posGivenName)
{
TPtrC familyName = fields[posFamilyName].TextStorage()->Text(); // pointer is NULL , ??????
}

TInt posPhNum = fields.FindNext(KUidContactFieldPhoneNumber);
if(KErrNotFound != posGivenName)
{
TPtrC phNum = fields[posPhNum].TextStorage()->Text(); // pointer is NULL , ??????
}
}
}
=========================================================================================

Thanks Again!!!!
Waiting for your help!!!!!!