InfoPath Dev

I am filling a drop down list box from a secondary data connection.  I want to query the data connection for the values upon the clicking of the drop down list. 

I don't want to populate the list box on form load.  I do not want to have to hit a button to query it.

When the user clicks on the arrow to display the values, how can I run the query on the secondary data source and populate the fields then?

 Thanks.

ek38

 I see that this post is old, but there was not a reply and I have this same problem,

 What version of InfoPath are you using? Browser or filler form?

 I am using InfoPath 2010 for the browser

 What is the secondary data connection to? A SharePoint list?

 yes, I do not want to write any code and want an "on-click function"

 With SharePoint 2010 and InfoPath 2010, you have query fields in the List data connection. You can just set the query field as equal to whatever form field your drop down is connected to and execute the query to get back associated items. No code needed.

 Ok thanks, I missed that