ActionScript 3.0 :: Fade Out Alpha Layer On Button Click - Error 1034

I have an .5 alpha layer that I want to fade out when any 1 of 5 buttons is clicked.
1) The alpha layer is on the screen, but its not at 50%, its solid
2) Its not fading when a button is clicked
3) Its not in the right position
4) I am getting an output error message that says:

TypeError: Error #1034: Type Coercion failed: cannot convert flash.display::MovieClip@3f7e34c1 to colorbars.
at flash.display::MovieClip/gotoAndPlay()
at Colorwheel/goColor()[Colorwheel::frame1:17] (

This code is telling the int_btn to go to the alpha layer frame, which continues thru frames 1 and 8) the code they are referring to is on frame 1 with a button that is also on frame 8 that I don't want the mouse up function to affect the alpha layer. The 4 other buttons on frame 8 should affect the alpha layer. The code on frame 8 tells the mouse up function to fade out the alpha layer:

var colorscreen:colorbars = new colorbars;addChild(colorscreen) //this is working its the alpha layer mccolorscreen.x = 0;
//this is not workingcolorscreen.y = 51;
colorscreen.height = 513;colorscreen.width = 612;colorscreen.alpha = .5; //not working
// all buttons below work but wont fadeout the alpha layer
[Code] .....

How do I tell it not to listen to the int_btn on mouse up? Should I be using an array or enter_frame or remove event listener or use all three to achieve my goal of fading out the alpha layer when any of the 4 btns are clicked?