title: Can't exchange authorization code for token on google oauth using php form
body: <p>I can get the authorization code easily, but I keep getting errors when trying to exchange it for an access token. </p>
  
  <pre><code>    &lt;FORM action="https://accounts.google.com/o/oauth2/auth" method="post"&gt;
  
  &lt;input type = "hidden" name = "code" value = "4%2FXR0s9YvmROnHOpNUuiSlfxHE7xj-"&gt;    
  
  &lt;input type = "hidden" name = "redirect_uri" value = "http%3A%2F%2Fwww.m1448analytics.com%2Foauth2%2Frecv.php"&gt; 
  
  &lt;input type = "hidden" name = "client_id" value = "502294831256-84q1ar05j14knsh5h2msvofu68e7rpaj.apps.googleusercontent.com"&gt;   
  
  &lt;input type = "hidden" name = "scope" value = ""&gt;   
  
  &lt;input type = "hidden" name = "client_secret" value = "hiding it"&gt;  
  
  &lt;input type = "hidden" name = "grant_type" value = "authorization_code"&gt;    
  
  &lt;INPUT type="submit" value="Send"&gt; 
  
  &lt;/FORM&gt;
  </code></pre>
  
  <p>Google says: Error: invalid_request
  Required parameter is missing: response_type
  Learn more
  Request Details</p>