Radio button and check box components come with Flash MX. Would it be easier to use them instead of writing my own code?
In many cases, yes. But you can customize your own code in ways that the components cannot. Plus, you have more control over how your movie looks and how it performs .
How can I have more than one group of radio buttons on the screen at the same time?
You could simply place all the radio buttons in a group together in their own movie clip. If you do that, you'll need to refer to the movie clip to use the getValue function: group1.myRadioButton.getValue() .
Is there a way to restrict user input to only upper- or lowercase letters ?
No, but you can use String.toUpperCase or String.toLowerCase to convert the results of their input when they are finished.