Javascript Not Running in iframe Codeigniter 3

I am updating a website from CodeIgniter 2 to CodeIgniter 3 (.1.9)

We had an iframe embedded in several pages with javascript in the iframe to, among other things, put in a placeholder for telephone number and set the iframe height dynamically. This was working fine in our CodeIgniter 2 implementation, but the javascript does not seem to be running at all in the CodeIgniter 3 implementation.

The page in which the iframe is embedded (page.php) has the following code:

Code:

<iframe id="iframe_form" src="<?php echo site_url('contact/request_consultation');?>" class="span3" scrolling="no" frameborder="0"></iframe>

The javascript on the actual request_consultation page (which is in the iframe) is as follows:

Code:

<script type="text/javascript">

$(document).ready(function(){

   $(".phone").mask("(999) 999-9999",{placeholder:"_"});
   $('.error').click(function(){
       $(this).removeClass('error');
   });


   $('#iframe_form', window.parent.document).height($('body').height());  

});
//]]>
</script>

I tried moving the code into the page in which the iframe was embedded (page.php), but it did not work. It is entirely possible that I may not have referenced the iframe and/ or its elements correctly:

Code:

document.getElementById("iframe_form").(".phone").mask("(999) 999-9999",{placeholder:"_"});

I also tried giving the 
<div> on the parent page an id: 

Code:

<div id="frame_span" >

 and then referencing the id from the request_consultation page, but that did not work, either.

Code:

$('#iframe_form', window.parent.document).height($('frame_span').height());

Any suggestions would be greatly appreciated.