I want to do following:

I have entry table and part of logging entry I have drop down list called "Strategies" where I will define few strategies.

Scenario:

I want to select option from drop down list. Some strategies requires two rows to put data. For e.g. "spread" strategy requires "X1" row and "X2" row in able to log information. So how do i insert row when I select particular drop down list and data entry and submit the entry to log table?