public dbSignalAttribute GetAttribute(int? signalId, String attributeName)
{
dbSignalAttribute attribute = null;
String sql = "SELECT * FROM signal_attribute_master WHERE signal_id = ? AND attribute_name = ?";
OleDbParameter[] dbParams = { CreateParameter(dbSignalAttribute._SIGNAL_ID, signalId),
CreateParameter(dbSignalAttribute._ATTRIBUTE_NAME, attributeName ) };
attribute = CreateBean<dbSignalAttribute>(sql, dbParams);
return attribute;
}