Loan Payment Calculator

I need to make a Car Loan Payment calculator where the user enters the price of the car, the current interest rate, the number of months the vehicle will be financed for and clicks Calculate. I am assuming the user enters valid informatino

Specifications:

Code:

 ·         Code a private method named calculateTotalInterest that calculates the total interest paid on the car and returns it as a decimal value. Monthly interest is calculated as (Price * Interest Rate)  / 12. This method should accept the following arguments:
          Argument
         Description
             price of car As Decimal
         The value entered for the Price of   Car
             interest rate As Decimal
         The value entered for the Interest   Rate
             number of months As Integer
         The value entered for the Number   of Months
             monthly payment As Decimal
         The value calculated for Monthly   Payments:
   [CENTER][CENTER]Price   x (Interest Rate / 12)
  (1 – ( 1 + Interest Rate / 12 ) –Number   of Months)[/CENTER][/CENTER]
        ·         The results for Monthly Payment, Total Interest Paid, and Total Paid should be formatted as currency and displayed in the appropriate controls on the form
  

When I try to run it (I am using Visual Studios) it hangs up at the payment calculation. Any help is GREATLY appreciated.


This is what I have so far:

 using System;
  using System.Collections.Generic;
  using System.ComponentModel;
  using System.Data;
  using System.Drawing;
  using System.Linq;
  using System.Text;
  using System.Windows.Forms;
   
  namespace _549_LargeJ_Exam01
  {
      public partial class Form1 : Form
      {
          public Form1()
          {
              InitializeComponent();
          }
   
          private void btnExit_Click(object sender, EventArgs e)
          {
              this.Close();
          }
   
          private void btnCalculate_Click(object sender, EventArgs e)
          {
              // declare variable
   
              double months = Convert.ToDouble(txtMonths.Text);
              double intrate = Convert.ToDouble(txtIntRate.Text);
              double price = Convert.ToDouble(txtPrice.Text);
              double payment = Convert.ToDouble(txtPayment.Text);
              double intpaid = Convert.ToDouble(txtIntPaid.Text);
              double totalpaid = Convert.ToDouble(txtTotalPaid.Text);
   
              // conversion of text box values
   
                    
              // Calculations
   
              payment = (price * (intrate/12))/(1 - (Math.Pow((1+intrate/12), months)));
              totalpaid = intpaid+(months*payment);
              
   
              intpaid = this.CalculateTotalInterest(price, intrate);
   
   
              // display output
   
   
   
              txtPayment.Text = payment.ToString("c");
              txtIntPaid.Text = intpaid.ToString("c");
              txtTotalPaid.Text = totalpaid.ToString("c");
   
          }
   
              private double CalculateTotalInterest(double p, double i)
              {
                  return (p * i)/12;
              }
   
   
   
          
      }
  }
   

 

So what problem are you exactly facing ?