请大家帮我看看could not create type 'service'怎么解决？

我建了个web service,但是当我点生成网站时，出错信息提示说：could not create type 'service',在网上用百度，谷歌查了很久还是没找到解决办法，请大家帮我看看问题到底出在哪里，代码如下：
using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Configuration;
using System.Data.SqlClient;
using System.Diagnostics;[WebService(Namespace = "http://www.contentmaster.com/NorthwindServices")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class Service : System.Web.Services.WebService
{
    public Service () {        //如果使用设计的组件，请取消注释以下行 
        //InitializeComponent(); 
    }    /*
    [WebMethod]
    public string HelloWorld() {
        return "Hello World";
    }
     */    
    private void handleWebException(Exception e)
    {
        EventLog log = new EventLog("Application");
        log.Source = "NorthwindServices";
        log.WriteEntry(e.Message, EventLogEntryType.Error);
    }    [WebMethod]
    public decimal HowMuchWillItCost(string productName, int howMany)
    {
        SqlConnection sqlConn = null;        try
        {
            ConnectionStringSettings cs =
               ConfigurationManager.ConnectionStrings["NorthwindConnectionString"];
            string connString = cs.ConnectionString;
            sqlConn = new SqlConnection(connString);
            SqlCommand sqlCmd = new SqlCommand();
            sqlCmd.CommandText = "SELECT UnitPrice FROM Products " +
               "WHERE ProductName = '" + productName + "'";
            sqlCmd.Connection = sqlConn;
            sqlConn.Open();
            decimal price = (decimal)sqlCmd.ExecuteScalar();
            return price * howMany;
        }
        catch (Exception e)
        {
            // Handle the exception
            handleWebException(e);
            throw new Exception();        }
        finally
        {
            if (sqlConn != null)
                sqlConn.Close();
        }    }}