Word Radio buttons not working in a form created in Word 2000

[LindaR]

I am setting up a form in Word 2000 and want to use radio buttons. However, when I add this via the controls toolbar, protect and save the document when I reopen the file the radio buttons don't work. When they are clicked on they take you to the code of the button. I have added dropdown options and this works ok but how can I get the radio buttons to work? I am using a Windows XP PC.