Hiding a subform after selecting a value in dropdownlist

Hi all,

    I need to hide a subform if i select the first value in a dropdownlist. I have tried by hiding a button in it, its working properly but not for the subform. Please any one try to solve my issue.

I have worte the following coding in FARMCALC of CHANGE event in dropdownlist

if (xfa.event.newText == "1") then
xfa.form.data.SUB1.sub1_list.presence = "invisible"        /*Subform*/
xfa.form.data.SUB1.Button2.presence = "invisible"          /*Button hiding is working*/
xfa.form.data.SUB1.text.presence = "invisible"            /*Even TEXT hiding is not working*/
else
xfa.host.messageBox( xfa.event.newText )
endif

Thanks in advance..