title: C# - How to add lines to listbox from other class
body: <p>I want to add some lines into <code>ListBox</code>, and I have few classes. I try to make my <code>ListBox</code> public in properties, and add some lines in my class, <code>Form1 form = new Form1();</code> and then <code>form.listBox3.Items.Add("ex");</code>.</p>
  
  <p>My program doesn't show any problems. What should I do next?</p>