Contact Form 7 – how to make a radio button with a mandatory text field?

Hi There,

I’m a bit of a newbie here but have digested FAQ and documentation but like Bono I still haven’t found etc etc…

I want to make a list of options – where did you hear about us – with radio buttons.

The last option is the standard “Other”

If this button is selected I want to have a mandatory text field – “Please specify” – but I can only seem to make them as 2 discrete items so if you select other you don’t have to fill out the field – and people aren’t.

IS this possible.

Thanks so much.

TD