I need to change the default currency to IDR (not USD) without exchange rate on Odoo 10.0. 

I did the following steps from http://www.surekhatech.com/blog/change-currency-in-pos-in-odoo-10 

And got the errors such as

1. When in POS, I tried to "Validate Closing & Post Entries", I got Odoo warning There is no account defined on the journal Cash for Profit involved in a cash difference and can not post the POS transaction.  

2. While in POS checkout, the unsolved problems on https://www.odoo.com/forum/help-1/question/10-0-a-transaction-can-t-have-a-0-amount-none-error-on-validate-odoo-pos-payment-121554

How to fix them ?

I also includeed the recorded screen on youtube at :   https://youtu.be/IahubLwnDDE

Can anybody advise me what to do ?