9.22.11

public partial class SessionStateDemo : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}

protected void rbl_SelectedIndexChanged(object sender, EventArgs e)
{
if (rbl.SelectedIndex != -1)
{
string[] Books = new string[3];
Session["cattext"] = rbl.SelectedItem.Text;
Session["catcode"] = rbl.SelectedItem.Value;
switch (rbl.SelectedItem.Value)
{
case "n":
Books[0] = "Programming C#";
Books[1] = "Programming ASP.NET";
Books[2] = "C# Essentials";
break;
case "d":
Books[0] = "Oracle & Open Source";
Books[1] = "SQL in a Nutshell";
Books[2] = "Transact-SQL Programming";
break;
case "h":
Books[0] = "PC Hardware in a Nutshell";
Books[1] = "Dictionary of PC Hardware and Data Communications Terms";
Books[2] = "Linux Device Drivers";
break;
}
Session["books"] = Books;
}
}

protected void btn_Click(object sender, EventArgs e)
{
{
if (rbl.SelectedIndex == -1)
{
lblMessage.Text = "You must select a book category.";
}
else
{
StringBuilder sb = new StringBuilder();
sb.Append("You have selected the category ");
sb.Append((string)Session["cattext"]);
sb.Append(" with code \"");
sb.Append((string)Session["catcode"]);
sb.Append("\".");
lblMessage.Text = sb.ToString();

ddl.Visible = true;
string[] CatBooks = (string[])Session["books"];

//populate the dropdownlist
int i;
ddl.Items.Clear();
for (i = 0; i < CatBooks.GetLength(0); i++)
{
ddl.Items.Add(new ListItem(CatBooks[i]));
}
}
}
}
}