It seems that you want to have a button on the flash application and once clicked it opens the facebook page that shares the video/image that pertains to the clicked button. What you want to do is simply create a button that on click opens a new website to facebook using their share api which has the following format:
var facebookShare:String = "http://www.facebook.com/share.php?u=' + encodedVideoLink + '&t='+ encodedVideoText";
Where the u parameter stands for the link that you wish to share, and the t parameter stands for the title of the piece that you want to share, whether it be a picture or video.
You want to add an event listener on MouseEvent.CLICK that has as its callback function a method that handles the opening of the facebook page passing the facebookShare variable as shown above. To open another page on your browser you can use this AS3 Class called URLNavigator: http://www.danishmetal.dk/project/source/com/zorked/URLNavigator.as
To sum it up, something along these lines would do:
var facebookShare:String = "http://www.facebook.com/share.php?u=' + encodedVideoLink + '&t='+ encodedVideoText";
facebookButton.addEventListener(MouseEvent.CLICK, this._goToUrl(facebookShare));
private function _goToUrl(link:String):Function {
var window:String = "_blank",
feats = "",
thisOverlay:Object = this; // to not lose scope when returning a func
return function (e:MouseEvent):void {
trace("Opening link to:"+link);
try { URLNavigator.ChangePage(link, window, feats); }
catch (e:Error) { trace("error launching "+link+" in "+window+" with feature set "+feats); }
}
}
I hope that helps. If you have questions regarding the code please let me know.