Yes of course. To do this, you just need to add some payments to a document in the familiar way to add payment.
If payment is the first to document and will not be fully enter the corresponding amount / proportion of total / and press Pay (after filling and other fields.). If you payment will be at the document, which has already made partial payment naisnete just last icon in the list of products is no longer payment Add and add additional payment. Click there and add payment.