Better yet, could you link us to the login page in question?

Before even looking into that, I'd be concerned with another area of security -- namely the laptops themselves. How confident are you in the laptop's level of security and the user's competence to not do something to negate the security? Your laptop might be a sitting duck on an unsecured network if it's not properly secured. And if your users have made any mistakes that have resulted in spyware (especially keyloggers) being installed, you're screwed regardless of any encryption a login page might have.

So I'd say that'd be your first concern...If that's all checked off, then definitely look into the encryption question.