Ok, that works, but the problem is that I have defined $(window).scroll() for all page like this:
$(window).scroll(function(){
//I do something
})
Then
$('#btn').click(function() {
$(window).off('scroll');//This works
});
with this, the first lines above does not work anymore
but with this
$('#txt').keyup(function(){
$(window).bind('scroll');
})
the first lines should work again, without repeat the source inside of the keyup event, I change ON by BIND because I though that the event would bind again to the scroll of the window