InfoPath Dev

I am working on a form created using 'New from Data Connection....'.
Main data connnection is named 'main'.

In the form I have a field named 'Service_Type_id'which is from main data connection. I change it to a
dropdown box whose data is binding to the secondary data connection based on the table 'type_desc'

Here is tbls design in my main data connection
id
service_type_id (example: 1,2,3,4)
comments

secondary data connection table 'type_desc
service_type_id
desc

I want automatically populate a comments filed in the form based on
a specfic service_type_id user select from the dropdown box.
For example, when user selects service_type_id = 4, the comments filed is visible to user.
Can someone help me out on this question? Thanks in advance!

Hi,

You can set Rule on dropdown field and using “Filter Data” option. For example setting value path like:

xdXDocument:GetDOM("SecondaryDOMName")/my:myFields/.. /my: comment[/my:service_type_id = xdXDocument:get-DOM()/my:myFields/my:service_type_id]

Thanks for your reply.
Here, I still get couple questions which make me confused when I tried your solutions.
When I goto dropdown box property->click rules: do I need to set condition here?
Click Add Action, select Set A Field's Value from the action drop-down list,
When I click the Xpath button to the right of Field. Which data source(main or secondary) and field I should select?
I also click the formula button to the right of Value, click Insert Field Or Group. Which data source(main or secondary) and field I should select?

Hey Fred,

Please check out this tutorial:http://infopathdev.com/howto/tutorials/default.aspx?i=9111ef580f95479890fc18fb2c5bac85