i'm not able to assign my AJAX return as variable to concat.

Here is the code:

```
         function GetSex() {
            $.ajax({
                url: '/SEX/GetAllSex/',
                success: function (data) {
                    console.log(data);
                }
            });
         }

         function GetUsers() {
             var Pistas = null;
             $.ajax({
                 url: '/Users/GetAllUsers/',
                 success: function (data) {
                     console.log(data)

                 }
             });
         }

```

I want to concat the results, so that's what i'm doing:

```
var Sex = GetSex();
var Users = GetUsers();

var x = Users.concat(Sex);

```

It says that Sex and Users variable is undefined!

I don't understand.

Thanks in advance =)