$(document).ready(function(){

  $(".main-menu ul li").mouseover(function() {
      $(this).find("span").stop(true, false).animate({"opacity": "1.0"}, "slow");
  }).mouseout(function(){
     $(this).find("span").animate({"opacity": "0"}, "slow");
 
  });
  
  $("#user_menu").mouseover(function() {
      $(this).find("span").stop(true, false).animate({"opacity": "1.0"}, "slow");
  }).mouseout(function(){
     $(this).find("span").animate({"opacity": "0"}, "slow");
  });

  $("#chose_city").mouseover(function() {
      $(this).find("span").stop(true, false).animate({"opacity": "1.0"}, "slow");
  }).mouseout(function(){
     $(this).find("span").animate({"opacity": "0"}, "slow");
  });

  });