I was wondering if anyone could help me with this program.

I am taking a course and have to make this program use references. I attempted at this but as you can see I did not get very far.

The program should do this:
1) run first function
2) get the degrees in celsius from the user
3) use the celsius data to calculate the farenheit data
4) then finally cout the answer to the user

Any Help would be Greatly Appreciated

#include <iostream.h>

double celsius_in;

double celsius_to_fahrenheit(double);
double get_celsius(double &celsius_in);

int main()
double fahrenheit;
double celsius;

celsius = get_celsius(double &celsius_in);

fahrenheit = celsius_to_fahrenheit(celsius);

cout << celsius << " C = " << fahrenheit << " F\n";

return 0;

double celsius_to_fahrenheit(double celsius)
return(celsius * (9.0/5.0) + 32.0);

double get_celsius(double celsius_in)

cout << "Enter the temperature in celsius: ";
cin >> celsius_in;