Try this,
private void populate_report(Bank e, IDataReader dr)
{
e.bank_id = dr.GetInt32(0);
e.bankind_date = dr.GetString(1);
if(! dr.IsDBNull(dr.GetDouble(2))
{
e.r200 = dr.GetDouble(2);
}
if(! dr.IsDBNull(dr.GetDouble(3))
{
e.r100 = dr.GetDouble(3);
}
}