title: Verify empty field Selenium C#
body: <p>I am trying to check if a text field is empty and I can't convert bool to string. 
  I am trying this:</p>
  
  <pre><code>var firstName = driver.FindElement(By.Id("name_3_firstname"));
  if (firstName.Equals(" ")) {
                  Console.WriteLine("This field can not be empty");
              }
  </code></pre>
  
  <p>Also, how can I check if certain number field is exactly 20 digits?
  Can you help me do this?</p>
  
  <p>Thank you in advance!</p>