After choosing the personnel account, you see a dialog to 
balance the open items. This was declared in chapter 5.6.

To balance all items which belong together, you have to 
mark them. Therefore, you click with the mouse to this 
item once. If you double-click on one item, you get more 
information's for this item. You can use the button 
"Balance", if the sum of all chosen items is zero. To 
identify these items, they get a unique balance number. You 
see this number with the point "Statement of Personnel 
Account..." and "Bills (Creditors)...", respectively 
"Bills (Debtors)...".