protected void Page_Load(object sender, EventArgs e)
{
    List customerList = new List();
    customerList.Add(new Customer(01111, "Santosh"));
    customerList.Add(new Customer(01112, "Narayan"));
    customerList.Add(new Customer(01113, "Poojari"));
    customerList.Sort(
          delegate(Customer lhs, Customer rhs) {
             return lhs.CustomerID.CompareTo(rhs.CustomerID);
             //OR return rhs.CustomerID.CompareTo(lhs.CustomerID);
          });
     //one can use customerList.Reverse() to reverse the sort order
     foreach (Customer customer in customerList)
         Response.Write(customer.CustomerID+"
");
}
public class Customer
{
    private int m_CustomerID        = int.MinValue;
    private string m_CustomerName   = string.Empty;
    public Customer(int customerId,string customerName) 
    {
       this.m_CustomerID = customerId;
       this.m_CustomerName = customerName;
    }
    public int CustomerID 
    { 
       get { return m_CustomerID; }
       set { m_CustomerID = value; }
    }
    public string CustomerName
    {
       get { return m_CustomerName; }
       set { m_CustomerName = value; }
    }
}