How do I pass radio button var info to an input textbox?

Ok, So I can not get the radio button info to pass to my php page so that it sends me an email. How do I set it up so that if someone clicks one of my radio buttons, that is sends its info to an input text box so that I can pass the textbox info to the php page? I can at least get input textbox info to pass to the php page, so I hope I can make this a work around for my radio buttons not working. Anyone have an example script for doing this?