Add moving effect on scroll to site

I have tryed this code in my site http://ift.tt/2paIjC1 and the result is that the effect don't stop. I want scrolling effect to stop when the section title is on bottom of the window and only image section to continue while they catch up. Also I don't know why my pic is zooming on scroll... How to debug that?

$(document).ready(function(){
$(document).bind('mousewheel', function(e){
if(e.originalEvent.wheelDelta /680 > 0) {
  $('#textbox').animate({
    'marginTop' : "+=50px" 
  });
}
else {
  $('#textbox').animate({
    'marginTop' : "-=10px" 
  });
}

});

$(document).bind('mousewheel', function(e){
if(e.originalEvent.wheelDelta /680 > 0) {
  $('#image').animate({
    'marginTop' : "+=50px" 
  });
}
else {
  $('#image').animate({
    'marginTop' : "-=5px" 
  });
}`}); 

});`