For a login system you should also have an register system. For a registration system you can use this block.
- First it will check the username already exists or not.
- If already exists then it will show a message.
- If not it will create a tag named the username and value as password.
And for the Login System you can use this blocks.
- First it will check if the username exists or not.
- If it is not existing then it will show a message.
- If exists, then it will check if the password is correct or not.
- If correct will show a message that "Login Successful".
- If not it will also show a message.
Is it ok?

