wordpress - Add onclick for every image add to a post or page

Question

I want to automatically add

class="highslide"  onclick="return hs.expand(this,config1)"

to every image I add to a post or page so that I have

<a class="highslide" onclick="return hs.expand(this,config1)" href="http://mysite.net/wp-content/uploads/2013/11/image.jpg" target="_blank"><img class="alignleft  wp-image-659" alt="" src="mysite.net/wp-content/uploads/2013/11/image.jpg" width="108" height="68" /></a>

I have looked for hrs and have found nothing that will do this, does anyone know of a plugin or a code snippet that will do this

Thanks

Answer 1