Need Help

[Bsbosa.com]

Hi.
please tell me my mistake in blow code,code not return any value.. please help


string query2 = "select sum(amount) Total from pur_inv_dtl where inv_id = '" + IdTxt.Text + "'";



SqlCommand cmd2 = new SqlCommand(query2, conn);


try
{
conn.Open();
SqlDataReader sdr = cmd2.ExecuteReader();
while (sdr.Read())
{
Gtotal.Text = sdr["Total"].ToString();
}

}
finally
{
conn.Close();
}