Problem with Session in .NET c# help please

Hi, i'm working with a website and im just trying to do something simple for now.
I can't get my Sessions working in the master page that i set up in the content page.
Here's a piece of my code in the master page:

if (Page.IsPostBack == true)
{
string name = Session["namn"].ToString();
namn.Text = Session["namn"].ToString();
Response.Write(Session["namn"].ToString());
}

and here's some code from my content page:

protected void button_click(object sender, EventArgs e)
{
OleDbConnection DB = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; data source=" + Server.MapPath("../App_Data/Solfilmdata.mdb"));
DB.Open();



OleDbCommand info = new OleDbCommand("SELECT * FROM users WHERE anv='"+username.Text+"' AND pw='"+pw.Text+"'", DB);

OleDbDataReader read = info.ExecuteReader();
read.Read();



if (read.HasRows == true)
{
Session["namn"] = read["anv"].ToString();
Session["epost"] = read["e-post"].ToString();
Session["id"] = read["behorighet"].ToString();


}
else
{
fel.Visible = true;

}
read.Close();
DB.Close();

}

In the master page i have a textbox that should state the username, so at first it's just visitor and then when i'm logging in i'm setting up a session for the username but when i try to use that session in the masterpage it says it doesnt exist. and if i do a empty session in the masterpage then it doesnt change. so basicly i have two sessions, one for master page and one for the content pages.
please help and thanks in advance


Found the solution, just changed the code in the master page to:

if (Session["namn"] == null)
{
namn.Text = "Besökare";
}
else
{
namn.Text ="Välkommen " + Session["namn"].ToString();
}

since it just kept changing the session back to the default setting in master page i removed it entirely from the masterpage.