void btn_Click(object sender, EventArgs e)
{
var selectedColumns = string.Empty;
foreach (Control ctrl in Pub1.Controls)
{
if (ctrl.GetType().Name != "CheckBox" || ctrl.ID == "CB_CheckAll" || !(ctrl as CheckBox).Checked)
{
continue;
}
selectedColumns += ctrl.ID.Substring("CB_Col_".Length) + ",";
}
Response.Redirect(string.Format(
"{0}?Step=3&FK_MapData={1}&FK_SFDBSrc={2}&STable={3}&SColumns={4}",
Request.Url.AbsolutePath, this.FK_MapData, this.FK_SFDBSrc, this.STable ?? (Pub1.GetLBByID("LB_Table").SelectedItem.Value), selectedColumns));
}