Function doesn't want to fire [closed]
$( "#login-form" ).dialog({
    autoOpen: false,
    height: 300,
    width: 350,
    resizable: false,
    modal: true,
    buttons: {
        "Вход": function() {
            var bValid = true;
            allFields.removeClass( "ui-state-error" );

            bValid = bValid && checkAcc( loginname,loginpassword );

            if ( bValid ) {
                //If its valid ...
                $( this ).dialog( "close" );
            }
        },
        Изход: function() {
            $( this ).dialog( "close" );
        }
    },
    close: function() {
        allFields.val( "" ).removeClass( "ui-state-error" );
    }
});

function checkAcc( u, p ) {
    alert();
    var result;
    $.ajax({
        url: "users.php",
        data: "Username=" + u.val() + "&Password=" + p.val(),
        type: "GET",
        cache: false,
        async: false,
        success: function(Valid){
            if(Valid == "0"){
                result = false;
                u.addClass( "ui-state-error" );
                updateTips("Грешно Потребителско име/Парола!");
            }
            else{
                result = true;
            }
        }
    });

    return result;
}

function checkAcc( u, p, element )