how to use sessions in asp.net using c sharp code in a login page

Advice and examples of using Session have been posted many, many times. Before asking a question here at least spend a few minutes doing some research.

Anyway, from code behind add your value as:

Session.Add("key", "value");

and get it back as:

object value = Session["key"];

That should get you going.

protected void btnlogin_Click(objec sender,EventArgs e)
{
Userclass u=new Userclass();
u.Username=txtusername.text.trim();
u.Password=txtpassword.text.trim();
if(u.checkUser())
{
Session["youreSessionName"]=u.Username;
Response.redirect("./Home.aspx")

}
else
{
lblIsUser.text=" User DOes not Exist";
}

you will use session["yoursessioname"] as a user name in the project for other information about the logged user from database or somewhere

Ok.

Have a login page designed. On submit button click event have something like:

{
  // Check for the authentication
  // if(authenticated)
  // {
  //    // Save the user profile/userid in a session.
  //    // Session["loggedInUserId"] = someId;
  // }
}

Whenever needed to verify or use the current loggedinId of the use, use Session["loggedInUserId"].ToString();

protected void btnlogin_Click(objec sender,EventArgs e)
{
Userclass u=new Userclass();
u.Username=txtusername.text.trim();
u.Password=txtpassword.text.trim();
if(u.checkUser())
{
Session["youreSessionName"]=u.Username;
Response.redirect("./Home.aspx")
}
else
{
lblIsUser.text=" User DOes not Exist";
}

you will use session["yoursessioname"] as a user name in the project for other information about the logged user from database or somewhere

Just write the following

For create session   :::   session["username"]="The value you want to send";

receive session  :::   if(session["username"]!=null){
                        your variable=session["username"].ToString();
                        }

crete session this way on login button click
Session["user"] = TextBox2.Text;