address book tutorial improvement

In addressbook tutorial
(link http://doc.trolltech.com/4.6/tutorials-addressbook-part4-addressbook-cpp.html)
we have several IF statments, example below:

??
void AddressBook::submitContact()
{
QString name = nameLine->text();
QString address = addressText->toPlainText();

if (name == "" || address == "")

{ QMessageBox::information(this, tr("Empty Field"), tr("Please enter a name and address.")); }

if (currentMode == AddingMode) {

if (!contacts.contains(name))

{ contacts.insert(name, address); QMessageBox::information(this, tr("Add Successful"), tr("\"%1\" has been added to your address book.").arg(name)); }

else

{ QMessageBox::information(this, tr("Add Unsuccessful"), tr("Sorry, \"%1\" is already in your address book.").arg(name)); }

??
Fist IF statement should prevent from adding new entry in address book without some text in nameLine and in addressText.
But even it wrong condition function doesn't stops, e.g. I can add entry with for example empty address. Therefore I recomend to add return if first condition is met:

void AddressBook::submitContact()
{
QString name = nameLine->text();
QString address = addressText->toPlainText();

if (name == "" || address == "")

{ QMessageBox::information(this, tr("Empty Field"), tr("Please enter a name and address.")); *return*; }