Whats wrong with my code? =(

1: #include <iostream.h>
2:
3:
4: int main();
5: {
6: cout <<"Hello World!\n";
7:     return 0;
8: }

#include <iostream.h>

int main()
{
    cout << "Hello World!\n";
    return 0;
}

#include <iostream.h>
using namespace std;

int main()
{

    int random;

    cout << "TEXT!!!\n";
    cin >> random; 

    return 0;

}

//Main.cpp
#include <iostream.h>
#include <fstream.h>
#include "test.h"



int main()
{
    write();
    return 0;
}

//test.h
#include <fstream.h>
#include <iostream.h>


fstream file;


int write()
{
    int x=0;

    file.open("G:\temp\test.txt", ios::out);
    file << "testing" << endl;
    file >> x;
    cout << x;
    file.close;
    
    return 0;
}

3 G:\Dev-Cpp\InOut.cpp In file included from G:\Dev-Cpp\InOut.cpp 
 G:\Dev-Cpp\test.h In function `int write()': 
16 G:\Dev-Cpp\test.h statement cannot resolve address of overloaded function