hai I'm again
I already done my program below. the problem when i run no output appear.
basically I declare 2 file . 1 for input(InTransFile) another one for input and output(InMasterFile).Both in .dat.
I want to compare accno1(masterfile) and accno2(transfile). if they equal
have to overwrite balance1(masterfile) and next record from master will be read

below are the program

#include <iostream>
using std::cout;
using std::cin;
using std::ios;
using std::cerr;
using std::endl;
#include <fstream>
using std::ifstream;
using std::fstream;
#include<iomanip>
using std::setiosflags;
using std::resetiosflags;
using std::setw;
using std::setprecision;

#include <cstdlib>



main()
{
ifstream InTransFile("trans.dat",ios::in);
fstream InMasterFile("master.dat",ios::in|ios::out);


if (!InMasterFile)
{
cerr<<"file could not open\n" ;
exit(1);
}
if (!InTransFile)
{
cerr<<"file could not open\n";
exit(1);
}


int accno1;
int accno2;
double balance1;
double balance2;
int found = 0;

while (!InMasterFile.eof())
{
while (!InTransFile.eof())
{
if (found == 0)
if (accno1 == accno2)
found = 1;

}
cout<<found<<"found";
cout<<accno1<<"master";
cout<<accno2<<"tran";
cout<<accno1<<balance1;


}
return 0;
}

One thing is that you are doing nothing much about the file i/o.Can you explain what you mean by no output.

Check the tutorial fourm for a fstream file i/o tutorial,might help .