You normally don't use checkboxes for that.Have a look at radio buttons - if you need to you can also customize them to look the same as checkboxes (by default they are round).They basically are a group of buttons of which only one can be activated.You can check all the details in the help entry:htt...

I just found out that you can even set the same things directly in LiveCycle Designer (File->Form Properties):

Hi Leah,you can protect a pdf from being edited in Acrobat Pro using the security features. (Advanced -> Security).The easiest way is securing the file with a password and allowing no edits.Here's the link to the online help:http://help.adobe.com/en_US/Acrobat/9.0/Professional/WSD012A4E1-51D1-4bcd-B...