Well, I have tested as below 4 codes. 1 & 3 can play sound and do fe.signal action. But 2 & 4 is not ok and will be hang. I don't why, may be it is a bugs for AM
1. case "select":
local previewClick = fe.add_sound("selectclick.mp3");
previewClick.playing=true;
fe.signal( "add_favourite" );
return true;
2. case "select":
local previewClick = fe.add_sound("selectclick.mp3");
previewClick.playing=true;
fe.signal( "select" );
return true;
3. case "add_favourite":
local previewClick = fe.add_sound("selectclick.mp3");
previewClick.playing=true;
fe.signal( "select" );
return true;
4. case "add_favourite":
local previewClick = fe.add_sound("selectclick.mp3");
previewClick.playing=true;
fe.signal( "add_favourite" );
return true;