Public Shared Function select_parametric(Optional ByVal fields_values As Hashtable = Nothing) As DataTable
	Dim sql_str As String = "SELECT * FROM dataTable WHERE type_group='@type_group' AND type_code='@type_code' AND UserId='@UserID'"
	Dim sql_conn As New SqlConnection(ConfigurationManager.ConnectionStrings("SqlServer").ToString)
	Dim sql_comm As New SqlCommand(sql_str, sql_conn)
	If fields_values IsNot Nothing Then
		For Each fld_name As String In fields_values.Keys
			Dim fld_str As String = "@" & fld_name
			sql_comm.Parameters.AddWithValue(fld_str, fields_values.Item(fld_name))
		Next
	End If
	Dim data_table As New DataTable
	Dim data_adapter As New SqlDataAdapter(sql_comm)
	Try
		sql_conn.Open()
		data_adapter.Fill(data_table)
	Catch ex As Exception
		i_err.handle(ex, sql_str)
	Finally
		sql_conn.Close()
	End Try

	If data_table.Rows.Count > 0 Then
		Return data_table
	Else
		Return Nothing
	End If

End Function