title: Calling a method from within a Class
body: <p>I have 2 Forms (Form1 and Form2) and a class (Class1). Form1 contains a button (Button1) and Form2 contains a RichTextBox (textBox1) When I press Button1 on Form1, I want the method (DoSomethingWithText) to be called.  I keep getting "NullReferenceException - Object reference not set to an instance of an object".  Here is a code example:</p>
  
  <p>Form1:</p>
  
  <pre><code>namespace Test1
  {  
      public partial class Form1 : Form  
      {
          Form2 frm2;
  
          Class1 cl;
  
          public Form1()  
          { 
              InitializeComponent();
          }
  
          private void button1_Click(object sender, EventArgs e)
          {
              frm2 = new Form2(); 
              cl.DoSomethingWithText();
              frm2.Show()
          } 
     }  
  }  
  </code></pre>
  
  <p>Class1:</p>
  
  <pre><code>namespace Test1
  {
        class Class1
        {
             Test1.Form2 f2;
             public void DoSomethingWithText()
             {
                  f2.richTextBox1.Text = "Blah blah blah";
             }
        }
  }
  </code></pre>
  
  <p>How can I call this method from within a class?  Any help is greatly appreciated.</p>