How to?
1. Register here
2. Done register form by fill in all the data required 
3. If you've succeed registering, the page will show you :

if don't, then you need to start over
4. Click log in on the right top of home page
5. Place your order to shopping cart and checkout to continue to the payment page
6. Fill in the voucher code box #myfirst and your payment method preference, after done the shipping page

7. Finish all the requirement and get your 20% off discount price!

HAVE A GREAT WEEKEND AND HAPPY SHOPPING :)