title: variable is Null despite receiving data
body: <p>attempting to insert a node into a Linked-List keeps crashing my Debug as apparently the position of the node I am passing is null and I can't figure out why</p>
  
  <pre><code>private void addBefore_Click(object sender, EventArgs e)
      {
          if (!string.IsNullOrEmpty(textBoxCarName.Text) &amp;&amp;
              (!string.IsNullOrEmpty(textBoxNodePosition.Text)))
          {
              LinkedListNode&lt;string&gt; current = myCarCollection.Find(textBoxNodePosition.Text);
              myCarCollection.AddBefore(current, textBoxCarName.Text);
              showLinkedList();
          }
          else
              MessageBox.Show("Please enter both a Car name and a valid Node position");
      }
  </code></pre>
  
  <p>above is the button I click that checks the "TextBoxNodePosition" TextBox and and then attempts to add a node in before the one selected, however when I check the crash notes, "current" is null, yet TextBoxNodePosition has a number to give</p>
  
  <p>edit: screenshot
  <img src="https://i.stack.imgur.com/oqcfH.png" alt="VS IDE Error"></p>