Связь между формами

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include<QFtp>
#include<QTreeWidget>
#include<QTreeWidgetItem>
#include<QUrlInfo>
#include<QtNetwork>
#include<QHash>
#include<QString>
#include<QFile>
#include<QStringList>
#include<QByteArray>
#include<QComboBox>
#include<QTextBrowser>
#include<QMessageBox>
#include<QDir>
#include"multiworkform.h"
 
class QProgressDialog;
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
   
signals:
    void sentData(QStringList ip,QStringList Dir);
 
private slots:
  .......
 
 
private:
    Ui::MainWindow *ui;
    MultiWorkForm *w2;
  
};
 
#endif // MAINWINDOW_H

#ifndef MULTIWORKFORM_H
#define MULTIWORKFORM_H
#include <QWidget>
#include"mainwindow.h"
 
 
namespace Ui {
class MultiWorkForm;
 
}
 
class MultiWorkForm : public QWidget
{
    Q_OBJECT
 
public:
    explicit MultiWorkForm(QWidget *parent = 0);
    ~MultiWorkForm();
signals:
    //void MultiWorkForm::closeEvent ( QCloseEvent * e );
private slots:
     void getData(QStringList data,QStringList Dir);
private:
    Ui::MultiWorkForm *ui;
   MainWindow *w1;
 
};
 
#endif // MULTIWORKFORM_H