--- chrome/content/webrunner.js 
+++ chrome/content/webrunner.js 
@@ -10,6 +10,8 @@
   params = new Params(window.arguments[0].QueryInterface(Components.interfaces.nsICommandLine));
 else
   params = new Params(null);
+
+var siteURI;
   
 
 function getBrowser() {
@@ -43,13 +45,18 @@
   var cl = window.arguments[0].QueryInterface(Components.interfaces.nsICommandLine);
   var startURI = cl.handleFlagWithParam("uri", false);
   if (startURI == null) {
-    startURI = "http://mozilla.org"
-  }
+    startURI = params.uri;
+  }
+
+  var ios = Components.classes["@mozilla.org/network/io-service;1"]
+                      .getService(Components.interfaces.nsIIOService);
+
+  siteURI = ios.newURI(startURI,null,null);
 
   var browser = getBrowser();
   browser.addEventListener("DOMTitleChanged", domTitleChanged, false)
   browser.webProgress.addProgressListener(browserProgressListener, nsIWebProgress.NOTIFY_ALL);
-  browser.loadURI(params.uri, null, null);
+  browser.loadURI(startURI, null, null);
 
   var browserContext = document.getElementById("main-popup");
   browserContext.addEventListener("popupshowing", popupShowing, false);
@@ -129,12 +136,17 @@
 
     var resolvedURI = ios.newURI(link.href, null, null);
 
-    var extps = Components.classes["@mozilla.org/uriloader/external-protocol-service;1"]
-                          .getService(Components.interfaces.nsIExternalProtocolService);
-
-    extps.loadURI(resolvedURI, null);
-    aEvent.preventDefault();
-    aEvent.stopPropagation();
+    if (resolvedURI.host != siteURI.host) {
+    
+      var extps = Components.classes["@mozilla.org/uriloader/external-protocol-service;1"]
+                            .getService(Components.interfaces.nsIExternalProtocolService);
+  
+      extps.loadURI(resolvedURI, null);
+      aEvent.preventDefault();
+      aEvent.stopPropagation();
+    } else {
+      link.target="_top";
+    }
   }
 }