asp.net - where to check the state of dynamically created checkboxes -

hello in programme need create dynamically checkboxlist items - got teh database.

the problem when clicking button should text cn checked checkboxes , should redirect user page

and have difficulty determining width of controls checkedore

1. if checked after added

   so if write

if (mycheckbox.items[s].selected==true)

after line

  page.findcontrol("form1").controls.add(mycheckbox); 

they not checked still false)

1. on postback event (clicking button ) - know on postback event dynamic controls no longer exist)

here code

protected void ddlnumbertourists_selectedindexchanged(object sender, eventargs e) {     int numtourists = convert.toint32(ddlnumbertourists.selecteditem.text);     (int = 0; < numtourists; i++)     {     string connectionstring = "server=localhost\\sqlexpress;database=excursion;trusted_connection=true";         string query =   "select extra_charge_id, excursion_id, amout, extra_charge_description extra_charges excursion_id=" + mynewstring;         sqlconnection conn = new sqlconnection(connectionstring);         sqlcommand cmd = new sqlcommand(query, conn);          try         {             conn.open();             sqldatareader rd = cmd.executereader();             int s = 0;             while (rd.read())             {                 mycheckbox.id = "chkblextracharge" + i.tostring() + s.tostring();                 mycheckbox.items.add(rd["extra_charge_description"].tostring());                 page.findcontrol("form1").controls.add(mycheckbox);                 s++;             }           }//end of try          catch (exception ex)         { }       }//end of 

i've implemented client-side check using jquery in online quiz engine (demo: http://webinfocentral.com): extract code snippet follows:

var _rows = $(this).find('tr');  (i = 0; < _rows.length; i++) {      // find out if checkbox checked     _checked = $(_rows[i]).find('input:checkbox').is(':checked'); }