cannot read property 'src' of undefined

[admin]

I get the error from the title in the follow JS:

$('.videoMedia .youtubeLink').each(function(i) {
 // Defining the iframe for each iteration
 var iframe = $(this).parents('li').find('.portfolio_det iframe');

 // Cutting the src from the iframe in pieces
 var begin = 'http://www.youtube.com/embed/'.length;
 var end = iframe[0].src.length-'?fs=1&feature=oembed'.length;

<strong>Uncaught TypeError: Cannot read property 'src' of undefined</strong>

 // Substracting the pieces
 var videolink = iframe[0].src.substring(begin,end);

 // Replacing the link with the leftovers
 $(this).attr('href', 'http://www.youtube.com/watch?v=' + videolink); 

     // Removing the iframe
 $(iframe).remove();
});

Any ideas why it thinks its undefined? Since iframe is defined on top of the function. Suggestions are welcome

<strong>Edit</strong>

Example of this script in "action" (not sure to call it like this, since there aint any action going on) is seen on: <a href="http://sqps.nl/bdare/?page_id=279" rel="nofollow">http://sqps.nl/bdare/?page_id=279</a>

Currently it only works for the last element on the right/bottom (with the bdare / youtube img)

<strong>Edit 2</strong>

Strange thing is, it used to work before (on localhost using xampp)

<strong>Edit 3 - problem fixxed</strong>

Hereby I would like to thank all of you who joined this discussion
I have found the solution.. Nothing was wrong with my code at all
The input from the wordpress post provoked the script from running properly, changing the content of the posts fixxed the problem

Cheers