title: VB6 equivalent of string.IsNullOrEmpty
body: <p>I'm doing some work on a legacy application, and my VB6 skills aren't that great. I need to check whether a String field has been initialized and set to something other than null/nothing or an empty string. In C# I'd just do something like:</p>
  
  <pre><code>if (string.IsNullOrEmpty(myObj.Str))
  </code></pre>
  
  <p>I'm not sure what the equivalent to this was in VB6, and I'm nervous about using <code>If myObj.Str = ""</code> and calling it good. What's the correct way to do this? </p>
  
  <p>To clarify, I want something that will return True if any of the following are true:</p>
  
  <ul>
  <li>The field hasn't been initialized</li>
  <li>The field is an empty string (str = "", length = 0)</li>
  <li>The field is set to null, or Nothing, or vbnull, or whatever form of the null value applies to VB6 strings.</li>
  </ul>
  
  <p>The field was originally a Long, and the code I'm replacing checked whether it was set to 0.</p>