diff --git a/OpenRA.Launcher.Mac/Controller.h b/OpenRA.Launcher.Mac/Controller.h
index 48b4aa37f4..5840cb83a6 100644
--- a/OpenRA.Launcher.Mac/Controller.h
+++ b/OpenRA.Launcher.Mac/Controller.h
@@ -16,7 +16,6 @@
 {
 	SidebarEntry *sidebarItems;
 	GameInstall *game;
-	JSBridge *jsbridge;
 	IBOutlet NSOutlineView *outlineView;
 	IBOutlet WebView *webView;
 }
diff --git a/OpenRA.Launcher.Mac/Controller.m b/OpenRA.Launcher.Mac/Controller.m
index c50b91b192..161de5409b 100644
--- a/OpenRA.Launcher.Mac/Controller.m
+++ b/OpenRA.Launcher.Mac/Controller.m
@@ -18,8 +18,8 @@
 - (void) awakeFromNib
 {
 	game = [[GameInstall alloc] initWithURL:[NSURL URLWithString:@"/Users/paul/src/OpenRA"]];
-	jsbridge = [[JSBridge alloc] initWithController:self];
-
+	[[JSBridge sharedInstance] setController:self];
+	
 	NSTableColumn *col = [outlineView tableColumnWithIdentifier:@"mods"];
 	ImageAndTextCell *imageAndTextCell = [[[ImageAndTextCell alloc] init] autorelease];
 	[col setDataCell:imageAndTextCell];
@@ -153,7 +153,7 @@ objectValueForTableColumn:(NSTableColumn *)tableColumn
 #pragma mark WebView delegates
 - (void)webView:(WebView *)sender didClearWindowObject:(WebScriptObject *)windowObject forFrame:(WebFrame *)frame
 {
-	[windowObject setValue:jsbridge forKey:@"external"];
+	[windowObject setValue:[JSBridge sharedInstance] forKey:@"external"];
 }
 
 @end
diff --git a/OpenRA.Launcher.Mac/JSBridge.h b/OpenRA.Launcher.Mac/JSBridge.h
index 770756e814..bd24b753c9 100644
--- a/OpenRA.Launcher.Mac/JSBridge.h
+++ b/OpenRA.Launcher.Mac/JSBridge.h
@@ -12,7 +12,11 @@
 @class Controller;
 @interface JSBridge : NSObject {
 	Controller *controller;
+	NSDictionary *methods;
 }
+@property(readonly) NSDictionary *methods;
+
++ (JSBridge *)sharedInstance;
+- (void)setController:(Controller *)aController;
 
--(id)initWithController:(Controller *)aController;
 @end
diff --git a/OpenRA.Launcher.Mac/JSBridge.m b/OpenRA.Launcher.Mac/JSBridge.m
index 4c03cb5224..394119df5d 100644
--- a/OpenRA.Launcher.Mac/JSBridge.m
+++ b/OpenRA.Launcher.Mac/JSBridge.m
@@ -9,29 +9,71 @@
 #import "JSBridge.h"
 #import "Controller.h"
 
-@implementation JSBridge
+static JSBridge *SharedInstance;
 
--(id)initWithController:(Controller *)aController
+@implementation JSBridge
+@synthesize methods;
+
++ (JSBridge *)sharedInstance
+{
+	if (SharedInstance == nil)
+		SharedInstance = [[JSBridge alloc] init];
+	
+	return SharedInstance;
+}
+
++ (NSString *)webScriptNameForSelector:(SEL)sel
+{
+	return [[[JSBridge sharedInstance] methods] objectForKey:NSStringFromSelector(sel)];
+}
+
++ (BOOL)isSelectorExcludedFromWebScript:(SEL)sel
+{ 
+	return [[[JSBridge sharedInstance] methods] objectForKey:NSStringFromSelector(sel)] == nil;
+}
+
+-(id)init
 {
 	self = [super init];
 	if (self != nil)
 	{
-		controller = [aController retain];
+		methods = [[NSDictionary dictionaryWithObjectsAndKeys:
+						@"launchCurrentMod", NSStringFromSelector(@selector(launchCurrentMod)),
+						@"log", NSStringFromSelector(@selector(log:)),
+						@"fileExistsInMod", NSStringFromSelector(@selector(fileExists:inMod:)),
+					nil] retain];
 	}
 	return self;
 }
 
-- (void) dealloc
+- (void)setController:(Controller *)aController
+{
+	controller = [aController retain];
+}
+
+- (void)dealloc
 {
 	[controller release]; controller = nil;
 	[super dealloc];
 }
 
+#pragma mark JS methods
+
 - (void)launchCurrentMod
 {
 	NSLog(@"launchcurrent");
 	[controller launchGame];
 }
 
-+ (BOOL)isSelectorExcludedFromWebScript:(SEL)aSelector { return NO; }
+- (void)log:(NSString *)message
+{
+	NSLog(@"js: %@",message);
+}
+
+- (BOOL)fileExists:(NSString *)aFile inMod:(NSString *)aMod
+{
+	NSLog(@"File %@ exists in mod %@",aFile, aMod);
+	return NO;
+}
+
 @end
diff --git a/mods/cnc/mod.html b/mods/cnc/mod.html
index a9177d70ef..f84065e5b1 100644
--- a/mods/cnc/mod.html
+++ b/mods/cnc/mod.html
@@ -95,7 +95,7 @@
 			</div>
 			<div id="buttons">
 			    <input type="button" class="button" onclick="window.external.launchCurrentMod();" value="Play" />
-			    <input type="button" class="button" value="Install Music" />
+			    <input type="button" class="button" onclick="window.external.fileExistsInMod('foo.mix','ra');"value="Debug" />
 			</div>
 		</div>
 	</body>