我要写毕业论文，请各位高手看看这几个基类的具体作用是什么？我不是太明白！谢谢了！

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections;
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;
using HNLG.Common;
using System.Text;namespace HNLG.Common
{
    public static class HNLGcheck
    { 
        /// <summary>
        /// 验证Main下登录是否正确,传入当前page
        /// </summary>
        /// <param name="page">当前页面指针，一般为this</param>
        public static Boolean SessionCheck(System.Web.UI.Page page)
        {
            return true;
            Boolean bln_check;
            string str_user_id;
            string str_GID;
            Boolean bln_ifin = true;
             
            bln_check = Convert.ToBoolean(page.Session["iflogin"]);
            if (bln_check  != true)
            {
                bln_ifin = false;
            }            str_user_id = Convert.ToString(page.Session["user_id"]);            if (str_user_id.Trim() == "")
            {
                bln_ifin = false;            
            }            str_GID = Convert.ToString(page.Session["GID"]);            if (str_GID.Trim() == "")
            {
                bln_ifin = false;            
            }            if (bln_ifin == false)
            {
                //GoToLogin(page);
                return false;
            }
            else
            {
                //PageInMain(page);
                return true;
            }              
        } 
    }
}