i recebo este erro

Parser Error Message: Could not create type 'charts.lineChartData'.

Source Error: 

Line 1:  <%@ WebHandler Language="C#" CodeBehind="lineChartData.ashx.cs" Class="charts.lineChartData" %>

Source File: /WebSiteNetPas/lineChartData.ashx    Line: 1 

--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1 

Na verdade, recebo esse erro ao usar o violinista, meu erro original é:

Uncaught ReferenceError: lineChartData is not defined                   lineChart.js:20
http://localhost/WebSiteNetPas/lineChartData.ashx?proxy 500 (Internal Server Error)

aqui está o meu lineChartData.ashx.cs :

using System;
using System.Web;
using System.Linq;
using System.Collections.Generic;
using Newtonsoft.Json.Linq;
using System.Web.Script.Serialization;

namespace charts
{
    public class lineChartData : IHttpHandler
    {

    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "text/plain";
        context.Response.Write("Hello World");
    }

    public bool IsReusable
    {
        get
        { return false; }
    }

    static string ConvertToJson()
    {
        lineChartClass c = new lineChartClass();

        double[] json = new double[4];

        //Array.Copy(c.piedata(), json, 4);
        c.piedata().CopyTo(json, 0);

        List<ChartItem> chartItems = new List<ChartItem>();

        chartItems.Add(new ChartItem() { Name = "Low", Data1 = json[0].ToString() });
        chartItems.Add(new ChartItem() { Name = "Moderate", Data1 = json[1].ToString() });
        chartItems.Add(new ChartItem() { Name = "Critical", Data1 = json[2].ToString() });
        chartItems.Add(new ChartItem() { Name = "High", Data1 = json[3].ToString() });
        string result = new JavaScriptSerializer().Serialize(chartItems);
        //result = "{ name: \"Low\", data1: " + json[0] + "}" + ",{ name: \"Moderate\", data1: " + json[1] + "}" + ",{ name: \"Critical\", data1: " + json[2] + "}" + ",{ name: \"High\", data1: " + json[3] + "}";

        return result;
    }
}
}

se precisar de mais detalhes, avise-me

obrigado antecipadamente pelo tempo ut