Subform details in a email

I have read the following:

https://www.zoho.com/creator/help/forms/creating-subforms.html#To_send_subform_details_in_an_email

and tried putting this into my form:

message="";

for each item in Progress

{

message=message + item.Progress + "<br />";

}

But this is getting ALL the items in progress, but I just want the ones that have been added as subforms to just the current form. How do I do this? Is there a way to identify in the subform what mainform ID is associated with it?