Display/Store and Retrieve Image Data from Database to Gridview, and also on Mouse Over

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.Text;
using System.Data.SqlClient;
using System.Configuration;
//using Entities;
using System.Data;
using Utils;

public partial class PhotoDetail : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            if (SessionManager.PageIndex != string.Empty)
            {
                this.hfKeyId.Value = SessionManager.KeyPrimary;
                this.hfPageIndex.Value = SessionManager.PageIndex;
            }
            var qry = Request.QueryString["id"];
            var userId = qry;
            this.lblName.Text = "The XP-Team";
            //this.lblRemarks.Text = firstName + " " + lastName;
            // Display the image from the database
            Image1.ImageUrl = "~/ShowFullSizeImg.ashx?id=" + userId;
            //Get user info
            User user = new User();
            user = GetUserInfo(userId);
            this.lblRemarks.Text = user.FirstName + " " + user.LastName + " " + user.MiddleName.Substring(0, 1);
        }
    }

    private User GetUserInfo(string userId)
    {
        string sqlConnection = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        SqlConnection conn;
        SqlCommand cmd;
        User lst = new User();

        try
        {
            using (conn = new SqlConnection(sqlConnection))
            {
                conn.Open();

                StringBuilder sbQry = new StringBuilder();
                sbQry.Append("select * FROM dbo.[User] where UserId = " + userId);
                using (cmd = new SqlCommand(sbQry.ToString(), conn))
                {
                    cmd.CommandType = CommandType.Text;

                    using (SqlDataReader dr = cmd.ExecuteReader())
                    {
                        while (dr.Read())
                        {
                            User temp = new User();
                            temp.UserID = Tools.Tools.IifInt(dr["UserID"]);
                            temp.Username = Tools.Tools.IifStr(dr["Username"]);
                            temp.Password = Tools.Tools.IifStr(dr["Password"]);
                            temp.LastName = Tools.Tools.IifStr(dr["LastName"]);
                            temp.FirstName = Tools.Tools.IifStr(dr["FirstName"]);
                            temp.MiddleName = Tools.Tools.IifStr(dr["MiddleName"]);
                            temp.WorksiteCode = Tools.Tools.IifStr(dr["WorksiteCode"]);
                            temp.AccessLevel = Tools.Tools.IifInt(dr["AccessLevel"]);
                            temp.Active = Tools.Tools.IifStr(dr["Active"]);
                            temp.DateCreated = Tools.Tools.IifDT(dr["DateCreated"]);
                            //temp.DateUpdated = Tools.Tools.IifDate(dr["DateUpdated"]);
                            temp.WorksiteCode = Tools.Tools.IifStr(dr["Worksitedesc"]);
                            lst = temp;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            lst.Username = "Error in retrieving record";
        }
        return lst;
    }
    protected void btnBack_Click(object sender, EventArgs e)
    {
        SessionManager.PageIndex = this.hfKeyId.Value;
        SessionManager.PageIndex = this.hfPageIndex.Value;
        Response.Redirect("~/DisplayRecord.aspx");
    }
}