diff --git a/background.js b/background.js
index 76f97b7..fbf1f80 100644
--- a/background.js
+++ b/background.js
@@ -1,3 +1,4 @@
+(function() {
 /**
  * A dictionary of header settings, keyed using the URLs supplied in the Options page
  */
@@ -18,6 +19,11 @@ var alteredCount = 0;
  */
 var displayCount = true;
 
+/**
+ * Cache with of request specific data
+ */
+var requestIds;
+
 /**
  * Returns the index of a given header object in the provided array
  * @param headerArray The Array to search in
@@ -36,18 +42,31 @@ function getHeaderIndex(headerArray, newHeader) {
     return -1;
 }
 
-function mergeNewHeaders(originalHeaders, newHeaders) {
+function mergeNewHeaders(originalHeaders, newHeaders, origin) {
     //copy the headers for our own usage
     var mergedHeaders = originalHeaders.slice();
     for (var i = 0, len = newHeaders.length; i < len; i++) {
-        var index = getHeaderIndex(mergedHeaders, newHeaders[i]);
-
-        //if a matching header is defined, replace it
-        //if not, add the new header to the end
-        if (index > -1) {
-            mergedHeaders[index] = newHeaders[i];
-        } else {
-            mergedHeaders.push(newHeaders[i]);
+        var thisHeader = newHeaders[i];
+
+        //skip if both are blank
+        if (thisHeader.name || thisHeader.value) {
+            var index = getHeaderIndex(mergedHeaders, thisHeader);
+
+            //issue #9 - fix - use new object to not over-write passed in reference
+            if (thisHeader.value === "HTTP_ORIGIN") {
+                thisHeader = {
+                    name: thisHeader.name,
+                    value: origin
+                };
+            }
+
+            //if a matching header is defined, replace it
+            //if not, add the new header to the end
+            if (index > -1) {
+                mergedHeaders[index] = thisHeader;
+            } else {
+                mergedHeaders.push(thisHeader);
+            }
         }
     }
 
@@ -101,8 +120,80 @@ function onHeadersReceivedHandler(info) {
         chrome.browserAction.setBadgeText({ text:(++alteredCount).toString()});
     }
 
-    return { responseHeaders:mergeNewHeaders(info.responseHeaders, desiredHeaders) };
+    var request = getRequestAndCleanUp(info);
+    var origin = request ? request.origin : "*"; // default to all if nothing is found
 
+    return { responseHeaders: mergeNewHeaders(info.responseHeaders, desiredHeaders, origin) };
+}
+
+/**
+ * Responds to Chrome's onBeforeSendHeaders event and finds 'origin' or 'referer' header for use later
+ * @param info {Object} Contains the request info
+ * @see http://code.google.com/chrome/extensions/webRequest.html#event-onBeforeSendHeaders
+ */
+function onBeforeSendHeadersHandler(info) {
+    var origin = null;
+
+    for (var i = 0, len = info.requestHeaders.length; i < len; i++) {
+        var header = info.requestHeaders[i];
+        if (header.name === "Origin") { // be done
+            origin = header.value;
+            break;
+        }
+        if (header.name === "Referer") { // keep going
+            origin = header.value;
+        }
+    }
+
+    //push on to stack
+    if (origin) {
+        requestIds.push({
+            requestId: info.requestId,
+            origin: origin,
+            expiration: Math.round(info.timeStamp) + 10E3
+        });
+    }
+
+    return {requestHeaders: info.requestHeaders};
+};
+
+/**
+ * Find the request and garbage collect the other requests. This should clean up orphan requests.
+ * @param info {Object} Contains the request info
+ */
+function getRequestAndCleanUp(info) {
+
+    var requestId = info.requestId;
+    var now = Math.ceil(info.timeStamp);
+
+    var request = null;
+
+    // Array.prototype.filter method
+    // - callback ~ return true (keep) or false (remove)
+    //  - finds the current element - fitlered
+    //  - return true (keep) if now is less than expiration
+    //
+    requestIds = requestIds.filter(function(elem) {
+        if (elem.requestId === requestId) {
+            request = elem;
+            return false;
+        }
+        return (now < elem.expiration);
+    });
+
+    return request;
+}
+
+/**
+ * Responds to Chrome's onErrorOccurred event
+ * @param info {Object} Contains the request info
+ * @see http://code.google.com/chrome/extensions/webRequest.html#event-onErrorOccurred
+ */
+function onErrorOccurredHandler(info) {
+    //still works but Chrome still complains ... this is the only property that is different from a normal request
+    if (info.type !== "xmlhttprequest") {
+        console.log('ForceCORS was unable to modify headers for: '+info.url +' - '+info.error);
+    }
 }
 
 /**
@@ -116,8 +207,6 @@ function showOptionsPage() {
     );
 }
 
-
-
 /**
  * Initializes the background page by retrieving settings and establishing the onHeadersReceived listener.
  * This method is called upon initialization, and also when the user changes settings on the Options page.
@@ -127,6 +216,7 @@ function init() {
     var settings = retrieveSettings();
     headersPerUrl = {};
     urlsToAlter = [];
+    requestIds = [];
 
     if (settings) {
         for (var l = settings.length, i = 0; i < l; i++) {
@@ -150,29 +240,26 @@ function init() {
     if (chrome.webRequest.onHeadersReceived.hasListener(onHeadersReceivedHandler)) {
         chrome.webRequest.onHeadersReceived.removeListener(onHeadersReceivedHandler)
     }
+    chrome.webRequest.onHeadersReceived.addListener(onHeadersReceivedHandler, {urls: urlsToAlter}, ["blocking", "responseHeaders"]);
 
-    chrome.webRequest.onHeadersReceived.addListener(
-        onHeadersReceivedHandler,
-        // filters
-        {
-            urls:urlsToAlter
-        },
-        // extraInfoSpec
-        ["blocking", "responseHeaders"]
-    );
+    //same logic
+    if (chrome.webRequest.onBeforeSendHeaders.hasListener(onBeforeSendHeadersHandler)) {
+        chrome.webRequest.onBeforeSendHeaders.removeListener(onBeforeSendHeadersHandler)
+    }
+    chrome.webRequest.onBeforeSendHeaders.addListener(onBeforeSendHeadersHandler, {urls: urlsToAlter}, ["requestHeaders"]);
 
-    chrome.webRequest.onErrorOccurred.addListener(
-        function(info){console.log('ForceCORS was unable to modify headers for: '+info.url +' - '+info.error)},
-        {
-            urls:urlsToAlter
-        }
-    );
+    //dido
+    if (chrome.webRequest.onErrorOccurred.hasListener(onErrorOccurredHandler)) {
+        chrome.webRequest.onErrorOccurred.removeListener(onErrorOccurredHandler);
+    }
+    chrome.webRequest.onErrorOccurred.addListener(onErrorOccurredHandler, {urls: urlsToAlter});
 
+    //let chrome know
     chrome.webRequest.handlerBehaviorChanged();
 }
 
 //establish a listener to respond to changes from the Options page
-chrome.extension.onRequest.addListener(function (request, sender, sendResponse) {
+chrome.extension.onRequest.addListener(function (request_not_used, sender_not_used, sendResponse) {
     //retrigger the init method to load the new settings
     init();
 
@@ -180,6 +267,7 @@ chrome.extension.onRequest.addListener(function (request, sender, sendResponse)
     sendResponse();
 });
 
-
 //make rocket go now!
-init();
\ No newline at end of file
+init();
+
+})();
\ No newline at end of file