ActionScript 3.0 :: Calling A Function Sending Different Data Types As Parameter?

In my code there's a function that shows an image on the screen (or loads the image and shows a progress bar). This function is called by clicking on a thumbnail, and it uses a parameter [e.target.name] refering to the property "name" of the thumbnail clicked, which is an integer (or I believe so). The thumbnails are placed inside the cointaner_mc MovieClip.

Code:
container_mc.addEventListener(MouseEvent.CLICK, clickThumb);
function clickThumb(e:MouseEvent):void{
if (my_full_images[e.target.name] == undefined){[code]...

but I want to call this function by clicking on a button, which would need to pass another type of parameter, in this case, a variable which refers to the number of the image displayed on the screen plus one.I tried this:

Code:
clickThumb(image_num + 1);
But it doesn't work, I get the following error:

1067: Implicit coercion of a value of type Number to an unrelated type flash.events:MouseEvent.

How could I call the function clickThumb and make it use "image_num + 1" instead of "e.target.name" ?

Could I dispatch the event (MouseEvent.CLICK, clickThumb), passing this value "image_num + 1" ?