want to hide mainwindow at program start up

[masuk]

Hi;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    QFile file("E:/workplace/info.txt");  
    QFile file1("E:/workplace/account_info.txt");
    if(file.exists() & file1.exists())
    {
        Form1 *frm1  = new Form1;
        frm1->setAttribute(Qt::WA_DeleteOnClose);
        frm1->setVisible(true);
        this->setVisible(false);
        frm1->setParent(0);
    }
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QFile file("E:/workplace/info.txt");  
    QFile file1("E:/workplace/account_info.txt");
    if(file.exists() & file1.exists())
    {
        Form1 *frm1  = new Form1;
        frm1->setAttribute(Qt::WA_DeleteOnClose);
        frm1->setVisible(true);
        this->setVisible(false);
        frm1->setParent(0);
    }
}

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but output shows both window(mainwindow & form1). i need only the form1