title: What is E_POINTER and E_INVALIDARG?
body: <p>I'm trying to write a browser helper object.. and sometimes I need to return E_INVALIDARG but I dont know what the value for this constant is. Is there a list of these constants in .net interop services somewhere?  I've been searching the namespace in the object browser and I cant find it..</p>
  
  <p>or do I not understand what I'm doing?  Can someone point me in the right direction?</p>