#include "userdialog.h"userDialog::userDialog(QWidget *parent, const char *name):QWidget(parent, name){	QPushButton *btn = new QPushButton("POPUP", this);	btn->setGeometry(50, 20, 100, 40);	connect(btn, SIGNAL(clicked()), this, SLOT(popupDialog()));}void userDialog::popupDialog(){	QDialog *dlg = new QDialog(0, "popup", FALSE);	dlg->setCaption("A QDialog Window");	QPushButton *btn = new QPushButton("POPDOWN", dlg);	btn->setGeometry(50, 20, 100, 40);	connect(btn, SIGNAL(clicked()), dlg, SLOT(accept()));	dlg->show();}int main(int argc, char **argv){	QApplication app(argc, argv);	userDialog udlg;	udlg.show();	app.setMainWidget(&udlg);	return(app.exec());}