diff --git a/content/html/content/src/nsHTMLButtonElement.cpp b/content/html/content/src/nsHTMLButtonElement.cpp
index 7690b1163fe5..d24bb1ba4f34 100644
--- a/content/html/content/src/nsHTMLButtonElement.cpp
+++ b/content/html/content/src/nsHTMLButtonElement.cpp
@@ -455,8 +455,17 @@ nsHTMLButtonElement::HandleDOMEvent(nsIPresContext* aPresContext,
       }
       break;
 
+    case NS_MOUSE_MIDDLE_BUTTON_DOWN:     // cancel all of these events for buttons
+    case NS_MOUSE_MIDDLE_BUTTON_UP:
+    case NS_MOUSE_MIDDLE_DOUBLECLICK:
+    case NS_MOUSE_RIGHT_DOUBLECLICK:
     case NS_MOUSE_RIGHT_BUTTON_DOWN:
-      // XXX Bring up a contextual menu provided by the application
+    case NS_MOUSE_RIGHT_BUTTON_UP:
+      if (aDOMEvent != nsnull && *aDOMEvent != nsnull) {
+        (*aDOMEvent)->PreventBubble();
+      } else {
+        ret = NS_ERROR_FAILURE;
+      }
       break;
 
     case NS_MOUSE_ENTER_SYNTH:
diff --git a/content/html/content/src/nsHTMLInputElement.cpp b/content/html/content/src/nsHTMLInputElement.cpp
index 3996c577cb25..0caef5d7cc5e 100644
--- a/content/html/content/src/nsHTMLInputElement.cpp
+++ b/content/html/content/src/nsHTMLInputElement.cpp
@@ -56,6 +56,7 @@
 #include "nsDOMError.h"
 
 #include "nsIPresState.h"
+#include "nsIDOMEvent.h"
 #include "nsIDOMNodeList.h"
 #include "nsIDOMHTMLCollection.h"
 
@@ -789,9 +790,28 @@ nsHTMLInputElement::HandleDOMEvent(nsIPresContext* aPresContext,
         }
       } break;// NS_KEY_PRESS
 
+      case NS_MOUSE_MIDDLE_BUTTON_DOWN:     // cancel all of these events for buttons
+      case NS_MOUSE_MIDDLE_BUTTON_UP:
+      case NS_MOUSE_MIDDLE_DOUBLECLICK:
+      case NS_MOUSE_RIGHT_DOUBLECLICK:
+      case NS_MOUSE_RIGHT_BUTTON_DOWN:
+      case NS_MOUSE_RIGHT_BUTTON_UP: {
+          PRInt32 type;
+          GetType(&type);
+          if (type == NS_FORM_INPUT_BUTTON || 
+              type == NS_FORM_INPUT_RESET || 
+              type == NS_FORM_INPUT_SUBMIT ) {
+            if (aDOMEvent != nsnull && *aDOMEvent != nsnull) {
+              (*aDOMEvent)->PreventBubble();
+            } else {
+              ret = NS_ERROR_FAILURE;
+            }
+          }
+        } break;
+
       case NS_MOUSE_LEFT_BUTTON_DOWN:
         mDidMouseDown = PR_TRUE;
-        break;// NS_KEY_PRESS
+        break;
 
       case NS_MOUSE_LEFT_BUTTON_UP:
       {
diff --git a/layout/html/content/src/nsHTMLButtonElement.cpp b/layout/html/content/src/nsHTMLButtonElement.cpp
index 7690b1163fe5..d24bb1ba4f34 100644
--- a/layout/html/content/src/nsHTMLButtonElement.cpp
+++ b/layout/html/content/src/nsHTMLButtonElement.cpp
@@ -455,8 +455,17 @@ nsHTMLButtonElement::HandleDOMEvent(nsIPresContext* aPresContext,
       }
       break;
 
+    case NS_MOUSE_MIDDLE_BUTTON_DOWN:     // cancel all of these events for buttons
+    case NS_MOUSE_MIDDLE_BUTTON_UP:
+    case NS_MOUSE_MIDDLE_DOUBLECLICK:
+    case NS_MOUSE_RIGHT_DOUBLECLICK:
     case NS_MOUSE_RIGHT_BUTTON_DOWN:
-      // XXX Bring up a contextual menu provided by the application
+    case NS_MOUSE_RIGHT_BUTTON_UP:
+      if (aDOMEvent != nsnull && *aDOMEvent != nsnull) {
+        (*aDOMEvent)->PreventBubble();
+      } else {
+        ret = NS_ERROR_FAILURE;
+      }
       break;
 
     case NS_MOUSE_ENTER_SYNTH:
diff --git a/layout/html/content/src/nsHTMLInputElement.cpp b/layout/html/content/src/nsHTMLInputElement.cpp
index 3996c577cb25..0caef5d7cc5e 100644
--- a/layout/html/content/src/nsHTMLInputElement.cpp
+++ b/layout/html/content/src/nsHTMLInputElement.cpp
@@ -56,6 +56,7 @@
 #include "nsDOMError.h"
 
 #include "nsIPresState.h"
+#include "nsIDOMEvent.h"
 #include "nsIDOMNodeList.h"
 #include "nsIDOMHTMLCollection.h"
 
@@ -789,9 +790,28 @@ nsHTMLInputElement::HandleDOMEvent(nsIPresContext* aPresContext,
         }
       } break;// NS_KEY_PRESS
 
+      case NS_MOUSE_MIDDLE_BUTTON_DOWN:     // cancel all of these events for buttons
+      case NS_MOUSE_MIDDLE_BUTTON_UP:
+      case NS_MOUSE_MIDDLE_DOUBLECLICK:
+      case NS_MOUSE_RIGHT_DOUBLECLICK:
+      case NS_MOUSE_RIGHT_BUTTON_DOWN:
+      case NS_MOUSE_RIGHT_BUTTON_UP: {
+          PRInt32 type;
+          GetType(&type);
+          if (type == NS_FORM_INPUT_BUTTON || 
+              type == NS_FORM_INPUT_RESET || 
+              type == NS_FORM_INPUT_SUBMIT ) {
+            if (aDOMEvent != nsnull && *aDOMEvent != nsnull) {
+              (*aDOMEvent)->PreventBubble();
+            } else {
+              ret = NS_ERROR_FAILURE;
+            }
+          }
+        } break;
+
       case NS_MOUSE_LEFT_BUTTON_DOWN:
         mDidMouseDown = PR_TRUE;
-        break;// NS_KEY_PRESS
+        break;
 
       case NS_MOUSE_LEFT_BUTTON_UP:
       {