'Else' is an unexpected token in my Java code and the error I'm getting is that of an illegal type at line 18. What is wrong with my code?

I'm very new to Java and only started it yesterday, this is an exercise for my class and the code has to be similar to this one. I'm trying to create a simple log-in system in Java. This is the error I am getting: Error:(18, 11) java: illegal start of type

I've had a friend with similar code and it worked for him and he cannot specify why mine is not working.

I tried removing the curly brackets. I tried making different if statements and I tried putting round brackets around read.nextLine();

System.out.print("Type your username: ");
        String username = reader.nextLine();
        System.out.print("Type your password: ");
        String password = reader.nextLine();

        if (username = "Alex" && password = "mightyducks") {
            System.out.print("You are now logged into the system!");
        } else if (username = "Emily" && password = "cat")
            System.out.print("You are now logged into the system!");
        } else {
        System.out.print("Your username or password was invalid!");
        }

I simply want the program to show "You are now logged into the system!" when the correct password is given for Alex or Emily and for it to otherwise state: "Your username or password was invalid!".