Hard Time Getting Button To Work (Open Link to Other Site)

Hi, i’m new to flash cs4 and action script entirely, and i’m stuck on the final stretch of a project i’m workng on. I’m out of hosting at the moment as far as uploading the site goes, and posting a link, but here is a copy of the action script and if anyone can tell me just by reading it if there is something wrong, i’d be greatly appreciative.

My Problem Is: I want whenever i click the button “twitter_btn” to open a new tab/window to the link and nothing happens when i click on it.

Here’s my code.

stop();home_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler49);function mouseDownHandler49(event:MouseEvent):void {
 
gotoAndStop(1, "home");
 
}
stop();about_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler50);function mouseDownHandler50(event:MouseEvent):void {
 
gotoAndStop(1, "aboutus");
 
}
stop();projects_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler51);function mouseDownHandler51(event:MouseEvent):void {
 
gotoAndStop(1, "projects");
 
}
stop();media_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler52);function mouseDownHandler52(event:MouseEvent):void {
 
gotoAndStop(1, "aboutus");
 
}
stop();donate_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler53);function mouseDownHandler53(event:MouseEvent):void {
 
gotoAndStop(1, "donate");
 
}
stop();arcade_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler54);function mouseDownHandler54(event:MouseEvent):void {
 
gotoAndStop(1, "arcade");
 
}
stop();contactus_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler55);function mouseDownHandler55(event:MouseEvent):void {
 
gotoAndStop(1, "contact");
 
}
stop();projectsavethechildren_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler84);function mouseDownHandler84(event:MouseEvent):void {
 
gotoAndStop(1, "projectlove");
 
}
stop();projectpbnj_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler85);function mouseDownHandler85(event:MouseEvent):void {
 
gotoAndStop(1, "projectpbnj");
 
}
stop();projectpamper_btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler86);function mouseDownHandler86(event:MouseEvent):void {
 
gotoAndStop(1, "projectpamper");
 
}
twitter_btn.addEventListener(MouseEvent.MOUSE_DOWN, myHandler111);
function myHandler111(event:MouseEvent):void {
    navigateToURL(new URLRequest("http://www.twitter.com/"), "_blank");
}

Thanks in Advance.