How to delete created folder in message app?

hi,
I have created a folder named NewFolder in message app by the following code.
and stored folder'id in iNewFolderId.

I have tried by two way,but don't work.
1.iMsvSession->RemoveEntry(iNewFolderId);
2.iSmsMtm->SwitchCurrentEntryL( iNewFolderId );
TMsvId parent = iSmsMtm->Entry().Entry().Parent();
iSmsMtm->SwitchCurrentEntryL( parent );
iSmsMtm->Entry().DeleteL( iNewFolderId );

How can I delete the folder with folder's id iNewFolderId?

_LIT(KNewFolderName,"NewFolder");

TTime date;
date.HomeTime();

CMsvEntry* newCEntry;
newCEntry = CMsvEntry::NewL(*iMsvSession, KMsvLocalServiceIndexEntryId, TMsvSelectionOrdering());
CleanupStack::PushL(newCEntry);

TMsvEntry newTEntry;
newTEntry.iType = KUidMsvFolderEntry;
newTEntry.iMtm = KUidMsvLocalServiceMtm;
newTEntry.iDetails.Set(KNewFolderName);
newTEntry.iServiceId = KMsvLocalServiceIndexEntryId;
newTEntry.iSize = 0;
newTEntry.iDate= date;
newTEntry.iRelatedId = 0;
newTEntry.SetStandardFolder(0);
newTEntry.SetVisible(ETrue);
newTEntry.SetReadOnly(EFalse);

newCEntry->CreateL(newTEntry);
// get new folder's id
iNewFolderId = newTEntry.Id();

CleanupStack::PopAndDestroy();

Thanks in advance
Regards
Lau