Radio Button

Hello,

I new in appian and a have a trouble with radio button,

I have an interface with textfield and rabio button, (name, ID) I need to validate the textfield acccoriding to selecton made in radio button. I mean, If  In  rabio burron I chosse (name), the textfield only recive charters, if I choose ID in textfiled put only numbers.

I've created a localvariable to save the seleccion, But I don't know how to continue..

Colud you help me, pelase?

Best regards