Removing from array values of checkboxes in jQuery

I have a checkboxes like this:

while($userRow=$resultForUsers->fetch_assoc()){
      $nameOfUser=$userRow['users_name'];
      $userId=$userRow['user_facebook_id'];
      $userFBPicture=$userRow['users_picture'];
      echo "
      <tr class='tr-data-users'>
      <td class='text-center'>
      <input type='checkbox' class='checkbox' onclick='if(this.checked){selo(this.value)}else{izbaci(this.value)}' value=$userId>
      </td>

So, for each user in my database I'm having one checkbox with value of his id. I need id's of all checked users(i.e checkboxes) in one array. I did it this way:

<input type='checkbox' class='checkbox' onclick='if(this.checked){put(this.value)}else{remove(this.value)}' value=$userId>
 var  niz={};
    var index=0;
        function put(o){
            niz[index++]=o;
            console.log(niz);
        }

So, console.log now displays id's of all checked checkboxes. What I want to do is if checkbox is unchecked then to remove that id(i.e chechbox value) from array. I tried it like this:

onclick='if(this.checked){put(this.value)}else{remove(this.value)}'
 var  niz={};
    var index=0;
        function put(o){
            niz[index++]=o;
            console.log(niz);
            remove(o,niz);
        }

        function remove(o,niz){
            if($.inArray(o,niz)){
                console.log('radim');
                var indexNiza= $.inArray(o,niz);
               niz= $.grep(niz,function(a,o){
                   return (a!=o);
               });
            }
        }   

As you can see this else part should handle if checkbox is unchecked and remove that id from array, but it doesn't work. Would really appreciate help on this.