Adding descriptor files in animate possible

I don't know much about descriptor files but I want to add softKeyBoardBehavor and it is not in the file that animate produces and so when I add it I get this error.

error unknown element in the descriptor file

<application xmlns="http://ns.adobe.com/air/application/26.0">
<id>codesnipp1.1</id>
<versionNumber>1.0.0</versionNumber>
<versionLabel/>
<filename>RECOVER_snipsnipes 0.9.70fla</filename>
<description/>
<name>RECOVER_snipsnipes 0.9.70fla</name>
<copyright/>
<initialWindow>

    <softKeyboardBehavior>none</softKeyboardBehavior>''////added this
     <systemChrome>standard</systemChrome>        
    <transparent>false</transparent>

I added this softKeyboardBehavior node it was not there to start .  but the website below says it can 
be there.  
https://help.adobe.com/en_US/air/build/WSfffb011ac560372f2fea1812938a6e463-8000.html


maybe you can't add it from animate or maybe I don't understand