How to save field value in Different field

Hi All,

 

Using Infopath designer 2013-SharePoint 2013 patform.

 

i have two fields:

1. AppID (Drop-Down) 

2. others ID (Textbox) 

 

when i selecting  AppID from drop-down then it savinf in APPID field only. 

 

but, when  select others option from appid Drop-Down then another blank tab will be appear and we can enter mannully which is Saving is Others ID field. what im trying it would saving in appid fields only.

 

Thanks