Program Analyser in Asp.net

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page
{
    int a=0,i=0;
    protected void Page_Load(object sender, EventArgs e)
    {
        ten:
        {
            Response.Write("10->");
             a++;
             i++;
        }
    twenty:
        {
            Response.Write("20->");
            i++;
            if (a == 5)
            {
                goto sixty;
            }
        }
        thirty:
        {           
            Response.Write("30->");
            i++;
             a=a+2;
        }
        fourty:
        {
            Response.Write("40->");
            i++;
        }
        fifty:
        {
            Response.Write("50->");
            i++;
            goto twenty;
        }
        sixty:
        {
            Response.Write("60");
            i++;
        }
        Response.Write("<br>");
        Response.Write(i);
    }
}