function checkTeamName()
{
    var name = $('name').val();
    //alert(name);
    $.ajax
        (
         'http://127.0.0.1/rgleague/checkname.php',
        {
        type:'POST',
        success:function(data){
            var response = JSON.parse(data);
            if(response.status === 'success'){
                $('#mesaj').html('Tag valid');
                $('#add').show();
            }else if(response.status === 'fail'){
                $('#mesaj').html('Tag dejaa folosit');
                $('#add').hide();
            }
        }
    });
}

/////////////////////////////
			<div id="js">
                            <script>
                                $(document).ready(function(){

                                    $('#name').keyup(function(){
                                        checkTeamName();
                                    });
                                });
                            </script>
                        </div>

/////////////////////////

<?php

include 'db.php';
include 'classes.php';

$name = $_POST['echipa'];
$query = $db->query('SELECT * FROM teams');
$result = $query->fetchAll(PDO::FETCH_ASSOC);
$nameExists = false;

for($i=0;$i<sizeof($result);$i++){
    if(strtolower($result[$i]['name']) === strtolower($name)){
            $nameExists = true;
    }
}

if($nameExists === false){
    die(json_encode(array('status'=>'success')));
}else if($nameExists === true){
    die(json_encode(array('status'=>'fail')));
}