diff --git a/postscript.js b/postscript.js
new file mode 100644
index 0000000..732e782
--- /dev/null
+++ b/postscript.js
@@ -0,0 +1 @@
+onpostscript();
diff --git a/render.html b/render.html
index e27a804..1ff0946 100644
--- a/render.html
+++ b/render.html
@@ -74,10 +74,13 @@
 <body>
 
 <div id='editmenu'><a id='editlink' href='' target='_top'>edit</a></div>
-<div id='vizstatus'><div id='statustext'></div><div id='statussub'></div></div>
+<div id='vizstatus'>
+  <div id='statustext'></div>
+  <div id='statussub'></div>
+  <div id='vizlog'></div>
+</div>
 <div id='vizraw'></div>
 <div id='vizchart'></div>
-<div id='vizlog'></div>
 
 <script>
 $('#editlink').attr('href', '/edit' + window.location.search);
diff --git a/render.js b/render.js
index f748c0e..37ed994 100644
--- a/render.js
+++ b/render.js
@@ -1640,13 +1640,17 @@
 
   function getUrlData(url, success_func, error_func) {
     console.debug('fetching data url:', url);
+    var successfunc_called;
 
     var iframe = document.createElement('iframe');
     iframe.style.display = 'none';
 
     iframe.onload = function() {
       // the default jsonp callback
-      iframe.contentWindow.jsonp = success_func;
+      iframe.contentWindow.jsonp = function(data) {
+        success_func(data);
+        successfunc_called = true;
+      }
 
       // a callback the jsonp can execute if oauth2 authentication is needed
       iframe.contentWindow.tryOAuth2 = function(oauth2_url) {
@@ -1699,9 +1703,18 @@
       };
 
       iframe.contentWindow.onerror = function(message, xurl, lineno) {
-        err(null, message + ' url=' + xurl + ' line=' + lineno);
+        err(message + ' url=' + xurl + ' line=' + lineno);
       };
 
+      iframe.contentWindow.onpostscript = function() {
+        if (successfunc_called) {
+          console.debug('json load was successful.');
+        } else {
+          err('Error loading data; check javascript console for details.');
+          err('<a href="' + encodeURI(url) + '">' + encodeURI(url) + '</a>');
+        }
+      }
+
       iframe.contentWindow.jsonp_url = url;
 
       //TODO(apenwarr): change the domain/origin attribute of the iframe.
@@ -1710,10 +1723,17 @@
       //  localStorage, set cookies, etc.  We can use the new html5 postMessage
       //  feature to safely send json data from the iframe back to us.
       // ...but for the moment we have to trust the data provider.
+      //TODO(apenwarr): at that time, make this script.async=1 and run postscript from there.
+
       var script = iframe.contentDocument.createElement('script');
-      script.async = 1;
+      script.async = false;
       script.src = url;
       iframe.contentDocument.body.appendChild(script);
+
+      var postscript = iframe.contentDocument.createElement('script');
+      postscript.async = false;
+      postscript.src = 'postscript.js';
+      iframe.contentDocument.body.appendChild(postscript);
     };
     document.body.appendChild(iframe);
   }