Can anyone please point out to me what exactly I am doing wrong?

//A program that opens two files, one for reading and one for writing.
 //It will then stream in a group of integers and calculate the ratio
 //of one integer that follows it.  The calculated ratio is then 
 //written to a file as a double.
 
 #include<iostream>
 #include<fstream>
 #include<cstdlib>
 using namespace std;
 
 bool open_input(ifstream& fin);
 //Requests the user to enter a filname for an input file.  (The
 //filename is assigned to a character array that is defined as follows
 //char_infile[16].)  Assigns the filename to the variable using a cin
 //statement.Uses the open and fail function to open the input file and
 //tests for failure to open.  Returns true if opening was successful 
 //and false if opening failed.
 
 bool open_output(ofstream& fout);
 //Requests the user to enter a filname for an output file.  (The
 //filename is assigned to a character array that is defined as follows
 //char_outfile[16].)  Assigns the filename to the variable using a cin
 //statement.Uses the open and fail function to open the output file 
 //and tests for failure to open.  Returns true if opening was 
 //successful and false if opening failed.
 
 int read_input(ifstream& fin);
 //Reads in ONE integer from the input file and returns that integer.
 //If the file has reached the end of the file the function should
 //return -1.
 
 void calc_write_ratio(ofstream& fout, int Value1, int Value2);
 //Calculates the ratio of the two integers to this function.  The
 //ratio is then written to the output file as a double followed by a
 //blank space.
 
 /**************************************************  ******************/
 
 bool open_input(ifstream& fin)
 {
 	char infile[16];
 
 	cout << "Enter the name of the input file that you wish to open"
 		<< endl;
 
 	cin >> infile;
 
 	fin.open(infile);
 	
 	if(fin.fail())
 	{
 		cout << "** Can't open input file **" << endl;
 		exit(1);
 	}
 	else
 		return 1;
 }
 
 /**************************************************  ******************/
 
 bool open_output(ofstream& fout)
 {
 	char outfile[16];
 
 	cout << "Enter the name of the output file that you wish to open"
 		<< endl;
 
 	cin >> outfile;
 
 	fout.open(outfile);
 	
 	if(fout.fail())
 	{
 		cout << "** Can't open output file **" << endl;
 		exit(1);
 	}
 	else
 		return 1;
 }
 
 /**************************************************  ******************/
 
 int read_input(ifstream& fin)
 {
 	int next; 
 	fin >> next;
 
 	if(fin.eof())
 		return -1;
 	else	
 		return next;
 }
 
 /**************************************************  ******************/
 
 void calc_write_ratio(ofstream& fout, int Value1, int Value2)
 {
 	double ratio;
 
 	ratio = (Value1 / Value2);
 
 	fout << ratio << " ";
 }
 
 /**************************************************  ******************/
 
 void main()
 {
 	ifstream file_in;
 	ofstream file_out;
 
 	int integer1, integer2;
 
 	open_input(file_in);
 
 	open_output(file_out);
 
 	integer1 = read_input(file_in);
 	
 	do
 	{
 		integer2 = read_input(file_in);
 		
 		calc_write_ratio(file_out, integer1, integer2);
 
 		integer1 = integer2;
 	} while (read_input(file_in) != -1);
 }

while ((integer2 = read_input(file_in)) != -1)
 	{
 		calc_write_ratio(file_out, integer1, integer2);
 
 		integer1 = integer2;
 	} 
 }