Index: ssts-invoice/src/main/java/com/forgon/disinfectsystem/invoicemanager/service/InvoiceManagerImpl.java
===================================================================
diff -u -r29442 -r29444
--- ssts-invoice/src/main/java/com/forgon/disinfectsystem/invoicemanager/service/InvoiceManagerImpl.java	(.../InvoiceManagerImpl.java)	(revision 29442)
+++ ssts-invoice/src/main/java/com/forgon/disinfectsystem/invoicemanager/service/InvoiceManagerImpl.java	(.../InvoiceManagerImpl.java)	(revision 29444)
@@ -9356,8 +9356,7 @@
 				
 				if (tempVo != null) {
 					tempVo.setAmount(tempVo.getAmount() + 1);
-					tempVo.setTotalPrice((tempVo.getTotalPrice() == null ? 0 : tempVo.getTotalPrice())
-							+ (tousseInstance.getPrice() == null ? 0 : tousseInstance.getPrice()));
+					tempVo.setTotalPrice(MathTools.add(tempVo.getTotalPrice(), tousseInstance.getPrice()).doubleValue());
 				} else {
 					
 					String expireDateStr = tousseInstance.getValidUntilStr(Constants.SIMPLEDATEFORMAT_YYYYMMDD);