Why the app crashes on pressing submit button in Qt?

Following is my definition of confirm window( the window that is opened on clicking submit button in main window). confirmwindow.h

#ifndef CONFIRMWINDOW_H
#define CONFIRMWINDOW_H

#include <QDialog>

namespace Ui {
class ConfirmWindow;
}

class ConfirmWindow : public QDialog
{
    Q_OBJECT

public:
    explicit ConfirmWindow(QWidget *parent = 0);
    ConfirmWindow(QString name);
    ~ConfirmWindow();

private:
    Ui::ConfirmWindow *ui;
};

#endif // CONFIRMWINDOW_H

And in confirmwindow.cpp I defined in following manner

#include "confirmwindow.h"
#include "ui_confirmwindow.h"

ConfirmWindow::ConfirmWindow(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::ConfirmWindow)
{
    ui->setupUi(this);
}

ConfirmWindow::~ConfirmWindow()
{
    delete ui;
}

ConfirmWindow::ConfirmWindow(QString name)
{
    ui->label_show_name->setText(name);
}

when I run the program it all goes well untill I press submit button, which crashes the app with a message in console as The program has unexpectedly finished. I guess, I am defining the constructor in a wrong way in confirmwindow.cpp file.