My app hangs when i try custom slots

[MolcomZ]

With that really simple code the app hangs when i click the button, but the examples included in QT works fine, and i don't see differences. I've tryed using different widgets with and without layouts, tryed deriving from QFrame, using "QObject::connect" and "connect" alone, with and without Q_OBJECT macro, but still the same. The only way it works is with an empty slot function. I've tryed with normal SIGNALS and SLOTS and it works. I think it must be a really stupid thing, but i can't see it.

This is the error when windows forces the exit of the program:
"Starting C:\Users\Administador\untitled1-build-desktop-Qt_4_8_1_for_Desktop_-MinGW__Qt_SDK__Debug\debug\untitled1.exe...
The program has unexpectedly finished.
C:\Users\Administador\untitled1-build-desktop-Qt_4_8_1_for_Desktop-_MinGW__Qt_SDK__Debug\debug\untitled1.exe exited with code -1073741819"

widget.h
@#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QPushButton>

class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
private:
QPushButton *button;

signals:

public slots:
void slotprueba();

};

#endif // WIDGET_H
@

widget.cpp
@#include "widget.h"

Widget::Widget(QWidget *parent) :
QWidget(parent)
{
QPushButton *button=new QPushButton("HOLA",this);
QObject::connect(button,SIGNAL(clicked()),this,SLOT(slotprueba()));

}
void Widget::slotprueba(){
button->setText("Pulsado");
}
@

main.cpp
@#include <QtGui/QApplication>
#include "widget.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget wid;

wid.show();


return a.exec();

}
@

[CarryGun]

Try to write such slot:

@void Widget::slotprueba(){
if(button)
button->setText("Pulsado");
}@

Looks like "button" isn't initialized.

Edit: the problem is that you redefined your button in constructor. Just write:
@button = new QPushButton("Text", this);@

[utcenter]

The actual pointer to the button you are connecting the slot to is lost after the constructor, and the one in the header points to nothing.

[MolcomZ]

Ok, solved. The problem was the second redefinition of the widget. Thanks to both.