How to make use of multiple webservice data connections in Adobe Forms?

I am using Adobe Live Cycle designer 8.2

In my Interactive Form, I have a web service data connection that gets triggered via a button and returns messages.

I added one more web service data connection and calling it on the click of a dropdown list.

The webservice does get executed and pings SAP. But the dropdown is empty.

I am using the following code to trigger the WebService on CLICK of the Dropdown list.

var cURL1 =http://servername etc;

var service = SOAP.connect(cURL1);

xfa.connectionSet.FetchCourseType.execute(0);

If I use execute(1) then I am getting a Adobe Software error.

I tried to fill this return data into a hidden table and bind to the dropdown - but that also is causing a Adobe Software error.

Please provide necessary guidance and / examples.

Thanks