Working with moodalbox in ajax

Question

I am creating a Html content using ajax.In the call back functon i am displaying this on a div using document.getElementById('divid').innerHTML funtionIn that i have a url for displaying the whole comtent in a popup using moodalbox.in normal case the page is showing in a popup.But when i using ajax the content is not showing in popup. Pls anybody help me

the string iam passing is

$str.='<div><a rel="moodalbox 600 300" href="'.$row->package_url.'"> <b>'.
       $row->package_title.'</b></a><br>'.
       truncate($row->package_description,400).
       ' <span style="float:right;">Booking expires on '.
       $row->expiry_date.'</span><br><br><br></div></div>';