How to make .pro files

[merry]

Hi all

I m using Qt3.1(Linux Operating System) and tried to make Simple Hello Word Program. with the filename hello.cpp

Here the code is:

#include <qapplication.h>
#include <qpushbutton.h>
 
int main( int argc,char **argv )
{
QApplication a( argc, arg v);
 
QPushButton hello( "Hello World!",0);
hello.resize( 100, 30);
 a.setMainWidget( &hello );
hello.show();
return a.exec();
}

#include <qapplication.h>
#include <qpushbutton.h>
                                                                                
int main( int argc,char **argv )
{
QApplication a( argc, arg v);
                                                                                
QPushButton hello( "Hello World!",0);
hello.resize( 100, 30);
 a.setMainWidget( &hello );
hello.show();
return a.exec();
}

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when i write qmake hello.cpp at commad line

i got:

[root@localhost root]# qmake hello.cpp
hello.cpp:4: Unknown test function: int main
hello.cpp:6: Unknown test function: QApplication a
hello.cpp:8: Unknown test function: QPushButton hello
hello.cpp:9: Unknown test function: hello.resize
hello.cpp:10: Unknown test function: a.setMainWidget
hello.cpp:11: Unknown test function: hello.show
hello.cpp:12: Unknown test function: return a.exec

What it mean and what should I do?
or For this I have to make pro file
if yes then Plese Tell me how can I make pro files


Thanx

Merry