How to show images in image control which are all ready present in the database

<asp:templatefield headertext="Photo" xmlns:asp="#unknown">
     <itemtemplate>
           <asp:image id="empImage" runat="server" imageurl="<%# "ImageHandler.ashx?ImID="+ Eval("ID") %>" width="100" height="120" alternatetext="Student Photo" descriptionurl="~/image/no-image-a.jpg" />
     </itemtemplate>
</asp:templatefield>

private void fillGrid(DataTable dt)
{
    myGrid.DataSource = dt;
    myGrid.DataBind()
       
}

<%@ WebHandler Language="C#" Class="ImageHandler" %>
 
using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.IO;
 
public class ImageHandler : IHttpHandler
{
 
    public void ProcessRequest(HttpContext context)
    {
        //context.Response.ContentType = "text/plain";
        //context.Response.Write("Hello World");
        string imageid = Convert.ToString(context.Request.QueryString["ImID"]);
        if (imageid != null && imageid.Trim() != "")
        {
            SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["connStr"].ToString());
            connection.Open();
            SqlCommand command = new SqlCommand("select PHOTO from EmpMst where ID=" + imageid, connection);
            SqlDataReader dr = command.ExecuteReader();
            dr.Read();
            try
            {
                    context.Response.BinaryWrite((Byte[])dr[0]);
                    connection.Close();
                    //context.Response.End();
            }
            catch
            {
                Byte[] b = File.ReadAllBytes(context.Server.MapPath("~/image/no-image-a.jpg"));
                context.Response.BinaryWrite(b);
                connection.Close();
                context.Response.End();
            }
        }
        else
        {
            Byte[] b = File.ReadAllBytes(context.Server.MapPath("~/image/no-image-a.jpg"));
            context.Response.BinaryWrite(b);
        }
    }
 
    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
 
}