Fields not hidden upon return/change of answer on Java Window.

I have created a Javascript Window attached to a Radio button where upon selecting Yes, some text fields populate and upon selecting No, the fields are hidden. I realize that if yes was selected by mistake, the fields still remain visible when you return to the window and click no. What can I do to make the script work where you can return to change selection and it remove and hide the fields consistently?

Here this my script,

//Message for the popup window//

cMsg = "Do you want to deactivate the incumbent's previous position for this Job Change?\n"

var nRtn = app.alert(cMsg,2,2,"Deactivate Previous Position");

// field that populate upon selecting the option Yes//

if(nRtn == 4)

this.getField("LayerButton7").display = display.visible;

if(nRtn == 4)

this.getField("Text16").display = display.visible;

//Fields are hidden upon selecting No//

elseif(nRtn == 3)

this.getField("LayerButton7").display = display.hidden;

elseif(nRtn == 3)

this.getField("Text16").display = display.hidden;