diff -r e9b07d41de7f -r 9cc253aa9405 javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/ConvertTypes.java
--- a/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/ConvertTypes.java	Tue Apr 16 08:39:54 2013 +0200
+++ b/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/ConvertTypes.java	Thu Apr 18 16:58:55 2013 +0200
@@ -22,6 +22,7 @@
 import java.io.InputStreamReader;
 import java.io.PushbackInputStream;
 import java.io.Reader;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Iterator;
 import java.util.concurrent.Executor;
@@ -29,6 +30,7 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javafx.application.Platform;
+import javafx.scene.web.WebEngine;
 import netscape.javascript.JSObject;
 import org.apidesign.bck2brwsr.core.JavaScriptBody;
 import org.json.JSONArray;
@@ -106,6 +108,18 @@
         }
     }
     
+    private static String findBaseURL() {
+        WebEngine eng = (WebEngine) System.getProperties().get("webEngine");
+        return (String)eng.executeScript(
+          "var h;"
+        + "if (!!window && !!window.location && !!window.location.href)\n"
+        + "  h = window.location.href;\n"
+        + "else "
+        + "  h = null;"
+        + "h\n"
+        );
+    }
+    
     public static String createJSONP(Object[] jsonResult, Runnable whenDone) {
         return "json" + Integer.toHexString(whenDone.hashCode());
     }
@@ -123,12 +137,21 @@
         private final Object[] jsonResult;
         private final Runnable whenDone;
         private final String jsonp;
+        private final URL base;
 
         LoadJSON(String url, Object[] jsonResult, Runnable whenDone, String jsonp) {
             this.url = url;
             this.jsonResult = jsonResult;
             this.whenDone = whenDone;
             this.jsonp = jsonp;
+            URL b;
+            try {
+                b = new URL(findBaseURL());
+            } catch (MalformedURLException ex) {
+                LOG.log(Level.SEVERE, "Can't find base url for " + url, ex);
+                b = null;
+            }
+            this.base = b;
         }
 
         @Override
@@ -138,7 +161,7 @@
                 return;
             }
             try {
-                URL u = new URL(url.replace(" ", "%20"));
+                URL u = new URL(base, url.replace(" ", "%20"));
                 InputStream is = u.openStream();
                 if (jsonp != null) {
                     PushbackInputStream pis = new PushbackInputStream(is, 1);