audio samples, fade in fade out

I’m stuck. I’m making a school project using open frameworks.

I’m trying to make a audio player that plays an audio sample when you push a button. This sample fades in and it has to fade out when you push another button, when a new audio sample fades in.

I made it this way now:

//--------------------------------------------------------------
void testApp::setup(){
hail.loadSound(“Hail.mp3”);
abba.loadSound(“Abba.mp3”);
black.loadSound (“Black.mp3”);
johnny.loadSound(“Johnny.mp3”);
peggy.loadSound (“Peggy.mp3”);
tex.loadSound(“Tex.mp3”);

}

//--------------------------------------------------------------
void testApp::update(){

}

//--------------------------------------------------------------
void testApp::draw(){

}

//--------------------------------------------------------------
void testApp::keyPressed(int key){

if (key == ‘q’){

; hail.play();

} else if (key == ‘w’){

;hail.stop();

; abba.play();

}

else if (key == ‘e’){

;abba.stop();

;black.play();

}

else if (key == ‘r’){
;black.stop ();
;johnny.play();

}

else if (key == ‘t’){

;johnny.stop();
;peggy.play();
}

else if (key == ‘y’){

peggy.stop();
tex.play ();
}

}

This doesn’t to the trick. Because now you can only get the right result when pressing the buttons in that order…
Can someone help me out?