void main( fstream data File; if (open fileln(data file, demofile txt") cout <<File open error! << endl exit(O) showContents(data File); data file close(;void main( ) { fstream dataFile; if (!openFileIn(dataFile,"demofile.txt")) { cout << "File open error!" << endl; exit(0); } showContents(dataFile); dataFile.close( ); }