cbkitems is CheckBoxList controlID
if (cbkitems.SelectedIndex >= 0)
{
string state1 = "";
foreach (ListItem s in cbkitems.Items)
{
if (s.Selected)
{
state1 += s + ",";
}
}
state1 = state1.Substring(0, state1.Length - 1);
DB_ColumnName = state1;
}
else
{
DB_ColumnName = "";
}
}