how to reset the value of particular field in dialog ?

I have three options in my dropdown,(A,B,C) . When i choose A , a pathield comes . When i choose B , a textfield comes . When i choose C ,  radiobutton group comes.

suppose i choose all options one by one and filled value respective of their field though my logic would be like whichever be my selection only that thing would reflect on my page. But all other options value also comes in the jcr:content properties of that page. I dont want that. I want like - if i choose A and put some value in its pathfield after then if i choose B , then all the values filled in A should get reset automatically. I have to use listener but how , i think selectionChanged event we can use. But i am not ble to make it. Please assist me.