Mc fade out

1

I have an mc kind of a popup window on stage with an x(close) button.
Is it possiblle to make the window_mc fades out when the x(close) is pressed.
The code for the X(close) button is:

//close button
blank.onRelease = function() {
this._parent._visible = 0;
};

I,ve tryed with _alpha = 0, but it want work for me