What's wrong with my code?

[Dave2011]

Code:
**************************
lcdrange.h:

#ifndef LCDRANGE_H
#define LCDRANGE_H
 
#endif // LCDRANGE_H
#include<QWidget.h>
#include<QSlider.h>
#include<QLcdnumber.h>
 
class Lcdrange: public QWidget
{
    Q_OBJECT
public:
    Lcdrange();
    int value();
private:
    QSlider* slider;
    QLCDNumber* lcd;
public slots:
    void setValue(int);
signals:
    void valueChanged(int);
};

#ifndef LCDRANGE_H
#define LCDRANGE_H

#endif // LCDRANGE_H
#include<QWidget.h>
#include<QSlider.h>
#include<QLcdnumber.h>

class Lcdrange: public QWidget
{
    Q_OBJECT
public:
    Lcdrange();
    int value();
private:
    QSlider* slider;
    QLCDNumber* lcd;
public slots:
    void setValue(int);
signals:
    void valueChanged(int);
};

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***************************
lcdrange.cpp:

#include"lcdrange.h"
 
Lcdrange::Lcdrange()
{
    slider=new QSlider(Qt::Horizontal,this);
    slider->setRange(0,99);
    slider->setGeometry(0,0,200,50);
 
    lcd=new QLCDNumber(2,this);
    lcd->setGeometry(0,50,200,50);
 
    connect(slider,SIGNAL(valueChanged(int)),lcd,SLOT(display(int)));
    connect(slider,SIGNAL(valueChanged(int)),SIGNAL(valueChanged(int)));
}
 
int Lcdrange::value()
{
    return slider->value();
}
void Lcdrange::setValue(int value)
{
    return slider->setValue(value);
}

#include"lcdrange.h"

Lcdrange::Lcdrange()
{
    slider=new QSlider(Qt::Horizontal,this);
    slider->setRange(0,99);
    slider->setGeometry(0,0,200,50);

    lcd=new QLCDNumber(2,this);
    lcd->setGeometry(0,50,200,50);

    connect(slider,SIGNAL(valueChanged(int)),lcd,SLOT(display(int)));
    connect(slider,SIGNAL(valueChanged(int)),SIGNAL(valueChanged(int)));
}

int Lcdrange::value()
{
    return slider->value();
}
void Lcdrange::setValue(int value)
{
    return slider->setValue(value);
}

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************************************
main.cpp:

#include<qapplication.h>
#include<qpushbutton.h>
#include"lcdrange.h"
 
class MyWindow: public Lcdrange
{
public:
    MyWindow();
private:
    QPushButton* button;
};
 
MyWindow::MyWindow()
{
    setGeometry(200,150,200,250);
 
    button=new QPushButton("Quit!",this);
    button->setGeometry(100,210,90,40);
 
    Lcdrange* range=new Lcdrange;
    range->setGeometry(0,0,200,100);
 
    Lcdrange* ranges=new Lcdrange;
    ranges->setGeometry(0,100,200,100);
 
    connect(range,SIGNAL(valueChanged(int)),ranges,SLOT(setValue(int)));
    connect(button,SIGNAL(clicked()),qApp,SLOT(quit()));
}
 
int main(int argc,char** argv)
{
    QApplication a(argc,argv);
 
    MyWindow mw;
 
    mw.show();
    return a.exec();
}

#include<qapplication.h>
#include<qpushbutton.h>
#include"lcdrange.h"

class MyWindow: public Lcdrange
{
public:
    MyWindow();
private:
    QPushButton* button;
};

MyWindow::MyWindow()
{
    setGeometry(200,150,200,250);

    button=new QPushButton("Quit!",this);
    button->setGeometry(100,210,90,40);

    Lcdrange* range=new Lcdrange;
    range->setGeometry(0,0,200,100);

    Lcdrange* ranges=new Lcdrange;
    ranges->setGeometry(0,100,200,100);

    connect(range,SIGNAL(valueChanged(int)),ranges,SLOT(setValue(int)));
    connect(button,SIGNAL(clicked()),qApp,SLOT(quit()));
}

int main(int argc,char** argv)
{
    QApplication a(argc,argv);

    MyWindow mw;

    mw.show();
    return a.exec();
}

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