Thread: conversion

I wrote this code and i can't seem to convert the hours to minutes . here is my code

Code:

#include <iostream.h>

int main()
{
	// declare variable
	int start_hour, start_min;
	int stop_hour, stop_min;
	float tax;
	float discount;
	int ampm;
	float cost;
	int difference,hour_difference, min_difference;
	float charges;
	int hold;
	
	// get times from user
	cout << "Enter Start Hour of call : ";
	cin  >> start_hour;
	cout << "Enter Start Minute of call : ";
	cin  >> start_min;
	cout << "1) AM" << endl;
	cout << "2) PM" << endl;
	cout << "Please choose your time by entering 1 or 2 : ";
	cin  >> ampm;
	cout << "Enter Stop Hour of call : ";
	cin  >> stop_hour;
	cout << "Enter Stop Minute of cal; : ";
	cin  >> stop_min;
	cout << "1) AM" << endl;
	cout << "2) PM" << endl;
	cout << "Please choose your time by entering 1 or 2 : ";
	cin  >> ampm;
	
	// switch statement
	switch(ampm)
	{
	case 1:
	cout << "The time of your phone call was in the morning." << endl;
	break;
	case 2: 
	cout << "The time of your phone call was in the evening." << endl;
	break;
	default:
	cout << "Please enter a valid number (1 or 2) next time you run program." << endl;
	break;
	}
	
	// give values to variable & if/else statements and converts min. to hour.
	tax = (cost * 0.05);
	if (ampm == 1 && start_hour >= 8 && start_min >=00)
	cout << "Your phone call will be charged full price. " << endl;
	
	if (ampm == 2 && stop_hour <= 5 && stop_hour <=00)
	cout << "Your phone call will be charged full price. " << endl;
	
	if (start_min >=60) 
	difference = (start_hour + 1);
	
	if (stop_min >=60)
	difference = (stop_hour + 1);
	
	if (start_hour >12)
	cout << "Invalid start hour." << endl;
	
	if (stop_hour >12)
	cout << "Invalid stop hour." << endl;
	
	// convert time
	hour_difference = (stop_hour - start_hour);
 	min_difference = (stop_min - start_min);
	cout << "Your call is " << hour_difference << " hour(s) " << min_difference << " minute(s) " << endl;
	
	// phone charges
	if (start_hour >=8 && start_min >=00 && stop_hour <=5 && stop_min <=00)
	cout << "Your charges are $ " << (min_difference * 0.20) << endl;
	
	cin >> hold;
	return 0;
}