why doesn't the button work?

[mattia]

I've added into Ui_spinForm.h a spinBox->setValue(5); and when i start the widget the value is 5. I've added ui.spinBox->setValue(5); into the spinForm.cpp constructor

spinForm::spinForm(QWidget *parent):QWidget(parent)
{
	ui.setupUi(this);
	connect(ui.addPushButton, SIGNAL(clicked()), this, SLOT(setSpinBoxValue()));
	ui.spinBox->setValue(3);
}

spinForm::spinForm(QWidget *parent):QWidget(parent)
{
	ui.setupUi(this);
	connect(ui.addPushButton, SIGNAL(clicked()), this, SLOT(setSpinBoxValue()));
	ui.spinBox->setValue(3);
}

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but nothing...