how to rectreate this dynamic controls - asp.net

Question

try to make a simple application in which I have a dropdown list with tems - numbers from 1 to 4.
Depending on the number the user choose - I create dynamically this number of checkboxes with binded checkedchanged event. So when the user checks some of the checkboxes so checkedchanged event is raised and I store the text of the checked checkbox in session and then when I click a button I want to see the text only from the checked checkboxes.
But it seems that in the checkedchanged event handler I should recreate the dynamic cotrol but I haven't found a solution. Thank you in advance.
public partial class proba : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
dd1.Items.Add("1");
dd1.Items.Add("2");
dd1.Items.Add("3");
dd1.Items.Add("4");
}
protected void dd1_SelectedIndexChanged1(object sender, EventArgs e)
{
int numTourists = Convert.ToInt32(dd1.SelectedItem.Text);
for (int i = 0; i < numTourists; i++)
{
CheckBox chk = new CheckBox();
chk.ID = "chk" + i;
chk.Text = "box" + i;
chk.AutoPostBack = true;
chk.CheckedChanged += new EventHandler(checkChanged);
Page.FindControl("form1").Controls.Add(chk);
}
}
protected void checkChanged(object sender, EventArgs e)
{
// here I should recteate the control
CheckBox chk = (CheckBox)sender;
lblpr.Text += chk.Text;
Srolession["chk"] = chk.Text;
}

Answer 1

static bool chkddlchange=false; //define this....to check you Drop Changed Or Not.
protected void Page_Load(object sender, EventArgs e)
{
dd1.Items.Add("1");
dd1.Items.Add("2");
dd1.Items.Add("3");
dd1.Items.Add("4");
if(Page.IsPostBack && chkddl==true)
{
int numTourists = Convert.ToInt32(dd1.SelectedItem.Text);
chkddl=true;//make true so you can know that you ddlindex is changed..
for (int i = 0; i < numTourists; i++)
{
CheckBox chk = new CheckBox();
chk.ID = "chk" + i;
chk.Text = "box" + i;
chk.AutoPostBack = true;
chk.CheckedChanged += new EventHandler(checkChanged);
Page.FindControl("form1").Controls.Add(chk);
}
}
}
protected void dd1_SelectedIndexChanged1(object sender, EventArgs e)
{
int numTourists = Convert.ToInt32(dd1.SelectedItem.Text);
chkddl=true;//make true so you can know that you ddlindex is changed..you have to
checkboxex on page load
for (int i = 0; i < numTourists; i++)
{
CheckBox chk = new CheckBox();
chk.ID = "chk" + i;
chk.Text = "box" + i;
chk.AutoPostBack = true;
chk.CheckedChanged += new EventHandler(checkChanged);
Page.FindControl("form1").Controls.Add(chk);
}
}