title: Accessing a Form thats already been instantiated
body: <p>In C#, using CF, how do you display a window that already has a previous instance loaded into memory?</p>
  
  <p>Example:
  Form1 has a textBox1 and a button. Some text is typed into texBox1.  The button click of Form1 loads Form2 which also has a button.  Clicking Form2's button calls Form3.  How do you call the already running instance of Form1 to call it's updateField method for example?</p>