title: TIdHTTP.Get EIdIOHandlerPropInvalid Error
body: <p>I am trying to use TIdHTTP.Get to load the USPS Zip4 result web page source into a variable (to extract the 4 digit zip code suffix), e.g.,</p>
  
  <pre><code>PgSrc := IdHTTP1.Get('https://tools.usps.com/go/ZipLookupResultsAction!input.action?resultMode=0&amp;companyName=&amp;address1=1600+PENNSYLVANIA+AVE+NW&amp;address2=&amp;city=&amp;state=Select&amp;urbanCode=&amp;postalCode=&amp;zip=20500');
  </code></pre>
  
  <p>The above example url works fine if I paste it into any browser. However, in my code I get an EIdIOHandlerPropInvalid error with the following message "IOHandler value is not valid."</p>
  
  <p>I have many zip codes to look up, so I would appreciate any help to avoid this error or a suggestion for a different approach.</p>