Sales Order with no items should not be saved

Is there a possibility to keep users from saving a sales order with no items.

Sometimes when creating a standard order and after entering
the Sold-to party
the PO Number
and the Req. deliv.date
our users accidentally save the order without entering any items, thinking they already completed the order. (For example when they have to answer a call in the meantime)

Is there a customizing setting to not save the order when there are no items in it? Or to display an error message?

Thanks in advance

Jakob