title: C# windows form, how to have radio buttons/checkboxes values input into multiple textboxes?
body: <p>I am new to C# and have a practice activity I'm really struggling with however am unable to get guidance from my tutor as he is currently ill.</p>
  <p>I believe I'm stuck on multiple things so I'll try to be as descriptive as possible..</p>
  <p>A screenshot of the application will be linked below. The idea of this application is to create a gym membership system, which allows users to see 'Membership cost', 'Extra charges', 'Total discount', 'Net Membership cost' and 'Regular payment amount', so 5 different calculations are required to be put into the textboxes at the bottom of the application.</p>
  <p>These different calculations are done by clicking on separate radio buttons and checkboxes. For example as seen in the picture one radio button may equal '$10' and another may equal '$15'</p>
  <p>I wish I had more code to show but I'm really confused so all help is appreciated.</p>
  <p>My questions are:</p>
  <ol>
  <li><p>How would I get the application to display 5 different calculations each for a different text box?</p>
  </li>
  <li><p>How would you get an equation to calculate a percentage discount?</p>
  </li>
  </ol>
  <p>Kind Regards :)</p>
  <p><a href="https://i.stack.imgur.com/SfBEe.png" rel="nofollow noreferrer">enter image description here</a></p>
  <p>My code:</p>
  <pre><code>using System;
  using System.Collections.Generic;
  using System.ComponentModel;
  using System.Data;
  using System.Drawing;
  using System.Linq;
  using System.Text;
  using System.Threading.Tasks;
  using System.Windows.Forms;
  
  namespace WindowsFormsApp11
  {
      public partial class Form1 : Form
      {
          public Form1()
          {
              InitializeComponent();
          }
  
          private void button1_Click(object sender, EventArgs e)
          {
              double results;
              int x, y, z, a, b;
  
              x = Convert.ToInt16(textbox5.text)
              y = Convert.ToInt16(textbox6.text)
              z = Convert.ToInt16(textbox7.text)
              a = Convert.ToInt16(textbox8.text)
              b = Convert.ToInt16(textbox9.text)
  
              if (radioButton1.Checked == true)
              {
                  value = 10
              }
              else if (radioButton2.Checked == true)
              {
                  value = 15
              }
              else if (radioButton3.Checked == true)
              {
                  value = 20
              }
  
              if (radioButton4.Checked == true)
              {
                  value = 10
              }
              else if (radioButton5.Checked == true)
              {
                  value = 15
              }
              else if (radioButton6.Checked == true)
              {
                  value = 20
              }
  
              if (radioButton7.Checked == true)
              {
                  value = 10
              }
              else if (radioButton8.Checked == true)
              {
                  value = 15
              }
  
              if (radioButton9.Checked == true)
              {
                  value = 10
              }
              else if (radioButton10.Checked == true)
              {
                  value = 15
              }
  
              if (checkBox1.Checked == true)
              if (checkBox2.Checked == true)
              if (checkBox3.Checked == true)
              if (checkBox4.Checked == true)
          }
      }
  }
  </code></pre>