My Source code is
SQl = "select ActiveRate from co_batchwiserate where batchid ='" + CrsList.GetBatchID.ToString().Trim() + "' and delstate <> 1";
SqlCommand cmd = new SqlCommand(SQl, SCon.GetConn());
strValue = (string)cmd.ExecuteScalar();
validate
Stvalue is null or empty means validate this strvalue
if (strValue == null)
{
LblErr.Text = "Invalid Course Amount";
return;
}