$('.selector').qtip({
   content: {
      text: function(api) {
         // Retrieve content from custom attribute of the $('.selector') elements.
         return $(this).attr('qtip-content');
        }
      },
      title: {
         text: function(api) {
            // Retrieve content from ALT attribute of the $('.selector') element
            return $(this).attr('alt');
         }
      },
     style: {
      classes: 'ui-tooltip-dark ui-tooltip-shadow';
      }
});

<script type="text/javascript" class="example">
$(document).ready(function()
{
    $('.selector').qtip({
   content: {
      text: function(api) {
         // Retrieve content from custom attribute of the $('.selector') elements.
         return $(this).attr('qtip-content');
      }
     },
      title: {
         text: function(api) {
            // Retrieve content from ALT attribute of the $('.selector') element
            return $(this).attr('alt');
         }
      },
     style: {
      classes: 'ui-tooltip-dark ui-tooltip-shadow';
      }
});
});
</script>

$('.selector').qtip({
   content: {
      text: function(api) {
         // Retrieve content from custom attribute of the $('.selector') elements.
         return $(this).attr('qtip-content');
      }
     },
      title: {
         text: function(api) {
            // Retrieve content from ALT attribute of the $('.selector') element
            return $(this).attr('alt');
         }
      },
     style: {
      classes: 'ui-tooltip-dark ui-tooltip-shadow';
      }
});

$(document).ready(function()
{
    $('.selector').qtip({
   content: {
      text: function(api) {
         // Retrieve content from custom attribute of the $('.selector') elements.
         return $(this).attr('qtip-content');
      },
      title: {
         text: function(api) {
            // Retrieve content from ALT attribute of the $('.selector') element
            return $(this).attr('alt');
         }
      }
   },
   style: {
      classes: 'ui-tooltip-dark ui-tooltip-shadow'
      }
    });
});