Login System (ASP.NET C#)

[dreamcon]

i have been trying to create a login system for a small project. The username and password are stored in MS SQL i can log in but the session will remain as not logged in any ideas why guys ?

protected void BtnSubmit_Click(object sender, EventArgs e)
{
if (Page.IsValid)
{
SqlCommand command = new SqlCommand("SELECT * FROM Member WHERE MemberUsername = @Username AND MemberPassword = @Password", c.connection);
c.connection.Open();
command.Parameters.AddWithValue("@Username", TxtUsername.Text);
command.Parameters.AddWithValue("@Password", TxtPassword.Text);
SqlDataReader DataReader = command.ExecuteReader();

while (DataReader.Read())
{
if (DataReader["MemberRoleID"].ToString() == "1")
{
Session["userid"] = TxtUsername.Text;
LblWelcome.Text = "Welcome: " + (Session["userid"]);
Response.Redirect("Register.aspx");
BtnSubmit.Enabled = false;
}
else if (DataReader["MemberRoleID"].ToString() == "2")
{
Session["userid"] = TxtUsername.Text;
LblWelcome.Text = "Welcome: " + (Session["userid"]);
Response.Redirect("PostComments.aspx");
BtnSubmit.Enabled = false;
}
}
c.connection.Close();
}
}