one sales order with splitting of delivery

Hi

I have created sales order with qty 10, i want to do delivery first only 5qty,then again 5qty,but with only single sales order number,is it possible,can u ell me the process step by step, i have put billing relevence as k in item category,it is spliting but only once it is asking but i want to split it to 2 deliveries.

Regards

Vejella