I figured it out. Sort of...
Here is how you do it...
Layout of Controls:
Drop down list box 1 (field1) button1 (btnGetCustomers)
Drop down list box 2 (field2) button2 (btnGetOrders)
Create a secondary data source. Go through the wizard, select the URL for the web service, select the web method you want to use, give it a friendly name (GetCustomersID) and deselect "Automatically retrieve data when form is opened." Click Finish.
In C#:
[InfoPathEventHandler(MatchPath="btnGetCustomers", EventType=InfoPathEventType.OnClick)]
public void btnGetCustomers_OnClick(DocActionEvent e)
{
// Write your code here.
WebServiceAdapterObject adapter = null;
adapter = (WebServiceAdapterObject) thisXDocument.DataObjects["GetCustomersID"].QueryAdapter;
adapter.Query();
}
Problem I have is (i'll create a seperate thread for this) is that the call to the second web service method requires an input parameter. I get an error
"Reference to undeclared namespace prefix: 'dfs'" when I try to get the node that contains the input parameter.