Fade Out with JavaScript

Hi,

I would like to know how to fade out a symbol when a button is pressed.

Here is what I did:

sym.$('btn1').click(function(){

sym.getSymbol('Symbol_1').fadeOut();

but when I have:

sym.$('btn1').click(function(){

sym.getSymbol('Symbol_1').playReverse();

It plays reverse the animation. On the other hand I do not know why it does not fade out.

Thank you in advance,

Frank