Encrypting passwords

It depends on the reasons why you are entering your username and password. If you are sending username and password to your own service, just use Transport Layer Security (TLS) as it will generate an encrypted session and all data sent during the session will be encrypted. If you are trying to log into an online service, you will probably have to follow whatever authentication protocol a particular web service uses. For example, many sites use OAuth. If you connect to such a service, you should also see if there are any client libraries available to communicate with that service, as many popular web services already have code to exchange and authenticate with them.