Sometimes, your browser's resolution isn't sufficient to see the entire more info screen that you need to fill out when you log in for the first time.
Go to the View menu on your browser and simply "zoom out" until you can see the entire more info window. Then you can continue with your registration.
Once you've registered, be sure to test your setup (http://app.wespeke.com/setup) to ensure that your browser can support the full features of WeSpeke's chatting environment.
For more on browser resolution, see Making the Most of your Web Browser's Resolution