hi everyone,

i had written an application wherein there will be single pushbutton and when i click the button and set of comments will appear. i had written as the following:

Qt Code: 
  1. class demo: public QWidget
  2. {
  3.    public:
  4. 	demo(QWidget *parent=0,const char *name=0);
  5. 	~demo();
  6.    public slots:
  7. 	void change();
  8.  
  9. };
  10.  
  11. demo::demo(QWidget *parent,const char *name):
  12. 	QWidget(parent,name)
  13. {
  14. 	setMinimumSize(640,480);
  15.  
  16. 	QPushButton *clear= new QPushButton("clear",this,"clear");
  17. 	clear->setGeometry(10,10,50,20);
  18. 	clear->setFont(QFont("Times",12,QFont::Bold));
  19. 	connect(clear,SIGNAL(clicked()),this,SLOT(change()));
  20. }
  21.  
  22. demo::~demo()
  23. {
  24. }
  25.  
  26. void demo::change()
  27. {
  28. 	printf("\n change \n");
  29. }
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this is all the code. but when i execute the program i get the error as

"QObject::connect: No such slot QWidget::change()
QObject::connect: (sender name: 'clear')
QObject::connect: (receiver name: 'unnamed')
".
but the same code works if i had declared the class in an header file and defined it in a cpp file and the main program in a main.cpp file.
can anyone say me why is this not working ? is my coding correct ?

thanks in advance,

saravanan