#include <iostream.h> 
#include <math.h> 
#include <cstdlib>
#include <iomanip> //here i am just throwing stuff in to try and fix the "missing function header"
int main( )
 {
 
   double months, amount, rate;		  
   double MonthlyPayment (double amount, double rate, int months);	  
   int GetChoice(void);   
   int option; 
   option = GetChoice();
 
	  {		 
		 cout << "Enter the loan amount: ";
		 cin >> amount;
		 cout << "Enter the interest rate (X.Y): ";
		 cin >> rate;
		 cout << "Enter the length of the loan in months : "; 
		 cin >> months; 
		 cout << "\tYour monthly payment is $ ";			   
	  option = GetChoice(); 
   } 
   return 0; 
}
int GetChoice(void) 
{ 
   int num; 
   cout << endl;   
   cout << "1. Calculate your monthly payment on the loan."
		<< endl << "You will enter the loan amount, Interest rate, and Length of the loan" << endl;  
   cout << "0. Exit the program" << endl; 
   cout << "Press 1 to procede : "; 
   cin >> num; 
   return num; 
} 
 
{ 
 
  int (amount * months) / rate = MonthlyPayment; 
  return MonthlyPayment;
}