If you are successfully logged in but the New Order button is gray, it could be because you have logged in using your Read-Only Password.
The Read-Only Password is used to give third-party access to anyone with whom you would like to share your account with in read-only mode. While logged in with a Read-Only Password, no trades can be made but your accounts, transaction history and other features are available to view.
To start trading, log in with your Trading Password.