Uncaught SyntaxError: Unexpected end of input เวลาคลิก button แก้ไขยังไงครับ

function viewList(){
    $('#showdata').empty();
    $.getJSON('content/hotel/server_booking.php', function(data){
        // ลองเพิ่มตรงนี้ ถ้า JSON มี error คงจะไม่มี alert
        alert('JSON successfully loaded');
        $.each(data, function(key, val){
            var products_code = val.booking_code.substr(0, 8)+ "-" + val.booking_code.substr(8);
            var html = '<tr>'+
                '<td class="text-center" style="vertical-align: middle"><strong>'+products_code+'</strong></td>'+
                '<td>'+val.hotel_name+'<br>'+val.roomtype+' / '+val.bedtype+' ('+val.room_amount+' ROOM)<br>'+val.check_in+' ~ '+val.check_out+'('+val.rent_night+' Night)</td>'+
                '<td class="text-center" style="vertical-align: middle">'+val.member_name+'</td>'+
                '<td class="text-center" style="vertical-align: middle">'+
                '<a class="button tiny" id="worksheetpopup" href="javascript: doPopup("'+val.booking_code+'");">Detail</a>'+
                '</td>'+
                '</tr>';
            
            $('#showdata').append(html);
        });
        
    });
}

'<a class="button tiny" id="worksheetpopup" href="javascript: doPopup("'+val.booking_code+'");">Detail</a>'+

'<a class="button tiny" id="worksheetpopup" href="javascript: doPopup(\''+val.booking_code+'\');">Detail</a>'+