Hey Friends, Thnx For the help last time, It was great on your part and the error gor solved. But again have stuck up at a point, where i have to upload the images and store it in the questions database.!the question must be in image format and the answers could also be in image format, and i have to save all this in the question database.! Please Help me out friends.!

I binded the database and store procedure with LINQ to SQL class

Hey, Friends... I am creating OnlineExam Application in .net, i am done with all the pages but am a bit muddeled how do i fetch the questions from the database...there is a page select question where user will select the questionpaper and the ID would be senr to the next page...i am done with this part but the problem is how do i call the questions from the "QuestionsTable"and then verify it with the correct answer.!

it says Object reference not set to an instance of an object. is in the line which i have underlined....:'(

Hey friends...I am creating an online examination project...I have made the login...the admin part and even all the databse thing is done...but in the user side as i press the start exam button it givving "Object reference not set to an instance of an object. " error...please help me out ASAP...m about to meet the deadlines..and if i meet it i ll be dead... here's my code..

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

public partial class Instruction : System.Web.UI.Page
{

OnlineExamsDataContext \_mycontext = new OnlineExamsDataContext();
string username;

protected void Page\_Load(object sender, EventArgs e)
{
    **username = Request.QueryString\["username"\].ToString();**
    lbluname.Text = "Welcome   :" + username;
    lbldate.Text = System.DateTime.Now.ToString();


}
protected void btnstart\_Click(object sender, EventArgs e)
{
    int emailid;
    emailid = \_mycontext.ExamTableInsert (Convert.ToDateTime (System.DateTime.Now.ToShortDateString()), Convert.ToInt32 (Request.QueryString\["UserID"\].ToString()), Convert.ToDecimal("0.0"));
    Response.Redirect("QuestionPaper.aspx");

}
protected void lbtnresult\_Click(object sender, EventArgs e)
{
    Response.Redirect("Examresult.aspx");

}

}