I suspect you'll need to set a flag indicating whether a user has already checked a radio button...

Then attach an event to each radio, so when the user selects it it checks the flag.... if its true, then alert: "You have selected the value"

else: prompt: "Whether he wish to change the value"

I sugest a less gender specific prompt... your love life will improve... unless you are a girl.. in which case it would make little difference...

please don't flame me.. i've been on drugs for a minor operation today...