using System;

using System.Xml;

using System.Xml.Linq;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string xml = @"<Bookstore HasToys=""YES""> 

            <Authors>7</Authors>

            <Location>Austin TX</Location>

            <Employees>15</Employees>

            <ToyList>

                <ToyId>124</ToyId>

                <ToyId>1251</ToyId>

            </ToyList>

            <ToyList>

                <ToyId>255-2</ToyId>

                <ToyId>6623</ToyId>

            </ToyList>

        </Bookstore>";

        XmlDocument doc = new XmlDocument();

        doc.LoadXml(xml);

​

        XmlNode root = doc.DocumentElement;

        var list = root.SelectNodes("//Bookstore[@HasToys='YES']/ToyList/ToyId").Cast<XmlNode>()    

            .Select(x => new

                      {

                            ToyId = x.InnerText

                      })

            .ToList();

        Console.WriteLine(String.Join(",", list.Select(x => x.ToyId)));

    }

}