JQuery Mobile app, make a mobile call with HTML 5

I am using JQuery Mobile with Phonegap and I am trying to create a button and when I click it a phone call should be made. I have mad a lot of research for this problem and I have found the following solution

<a href="tel:+123456789">Call</a>

or

<a href="#" onclick="window.open('tel:+123456789', '_blank', 'location=yes');" data-role="button">Call</a>

This solution is working on browsers (is asking me to open Skype) but when I run it on Android with a Samsung Galaxy S2 is not working. It is not doing anything.

I have tried to add to the config.xml file the following permission:

<access launch-external="yes" origin="tel:*" />

but is not working either. If you have any solution to suggest please do so. Thank you!