Adding random number to file name upload

programming flash
1

Hello,

I have a script to upload images to my server. I want to generate a random number to add to the users file name incase they upload an existing name and write over it. I have created a var called file nameAddOn and it gets a random number. When I trace the var nameAddOn I get the number, but when I upload the file it doesent sent the nameAddOn var with the file name. I cant see anything wrong with the code.::crying:

Heres the code

uploadBttn.addEventListener(MouseEvent.MOUSE_DOWN, launchPrompt);


function launchPrompt(event:MouseEvent)

{
    var img_mc:MovieClip = new MovieClip();
    addChild(img_mc);
    
    
    var fileNameAddOn:String = "";
    fileNameAddOn = String(Math.round(Math.random()* 100000));
    
    var imageTypes:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg; *.jpeg; *.gif; *.png");
    var allTypes:Array = new Array(imageTypes);
    var fileRef:FileReference = new FileReference();
    fileRef.addEventListener(Event.SELECT, selectHandler);
    fileRef.addEventListener(Event.CANCEL, cancelHandler);
    fileRef.addEventListener(Event.COMPLETE, completeHandler);
    fileRef.browse(allTypes);
    
    function cancelHandler(event:Event):void
    {
        trace("you've cancelled your selection");
    }
    
    function selectHandler(event:Event):void
    {
        //trace(fileRef.name);
        //trace(fileRef.size);
        /*if(fileRef.size > 100000){
            trace("to big");
        }else{
            trace("fine");
        }*/
        
        var request:URLRequest = new URLRequest("http://www.monkeyrockdesigns.com/upload/upload.php");
        var params:URLVariables = new URLVariables();
        request.method = URLRequestMethod.POST;
        params.fileNameAddOn = fileNameAddOn;
        request.data = params;
        trace(params);
    
        
        try {
            fileRef.upload(request);
            //trace(fileRef.name);
            
            //trace("The name of the file is..." + fileNameAddOn + fileRef.name);
            
        }
        catch(error:Error) {
            trace(error);
            trace("theres an error"); 
            
        }
        
    }
    
    function completeHandler(event:Event):void
    {
        
    }
    
}

Any help please?