[TYPO3-project-seminars] How to show bank account field only when needed

[Alexander Grein]

Hi,

is there a (easy) way to show the bank account field only when needed?
The idea is to show the 4 fields (accountnumber, ownername, banknumber 
and bankname) only when the user click on the radiobutton "debit".

As is found out, the form is generated by formidable, which already use 
prototype to do some client side validation(?).