alert not working in page two

alert not working in page two

i'm making jquery mobile tabs with login in android app with cordova phonegap

In my index i have page create. Here i do validation and check id and password is correct.
with id=index for data-role=page

    $(document).on("pagecreate", "#index", function() {..});

If validation pass I change page my current to login.html with

    $.mobile.changePage( "login.html" );

Now In my login.html
if i use 

    $(document).on("pagecreate", "#login", function() {..});

ajax is not working

I have 3 tabs in login.html with separe file for each

Can i use?

    $( ":mobile-pagecontainer" ).on( "pagecontainershow", function( event, ui ) {..});

My problem is when i change page alert not works 
I don't know what i hav to use pageshow or pagecreate or pageinit..

Or any ideas?