var last_id = 'f1';
var is_fade = true;

function change(vals) {
   $(document).ready(function(){
    //  alert($(vals).attr('id'));
       
      if (last_id != $(vals).attr('id') && is_fade == true){
         last_id = $(vals).attr('id');
         
         is_fade = false;
         
         $('.used').attr("class", "");
         $('#'+$(vals).attr('id')).attr("class", "used");
              
         $('.used_cont').fadeOut(0,function () {
                     
            $('.used_cont').attr("class", "d_none");
            $('.used_cont').css({"display": "none"});
            
            $('#content_'+$(vals).attr('id')).fadeIn(100,function (){
              // $('.used_cont').attr("class", "d_none");
               // $('.used_cont').css({"display": "none"});
               $('#content_'+$(vals).attr('id')).attr("class", "used_cont");
               
               is_fade = true;
               
            });
         });
      }
      
   });      
}