Adding tracking (google analytics event) to phone numbers/phone calls

I wanted to have phone call tracking on my website, so I know how many users did click phone number to call over cell phone or phablet or whatever device they can call (maybe google glass or something) So I added some code to my phone fields. I have cck field that I display over display suite, so I override this field and remove default display and create custom display, code field where I use entity data and add custom code to the phone numbers so they are clickable links. Code looks like this

if (!empty($entity->field_phone)){
foreach ($entity->field_phone['und'] as $key => $value) {
     print '<div class="field-item even">' . '<a href="tel:'. $entity->field_phone['und'][$key]['value'] .' " onclick="_gaq.push(["_trackEvent","Phone Call Tracking"," ' .$entity->title. ' "]);">'
     .$entity->field_phone['und'][$key]['value'] . '</a></div>';