jQuery.attr() method : is very robust,
**~ it adds attributes with values, and also allows to replace attribute/values
Id Attribute must be Unique :
http://www.w3.org/WAI/GL/WCAG20/tests/test185.html
Class attribute :grouping elements with distinct properties.
re-load()
||
challenge:id
||
challenge:class
id: x1 testing bed
--
id: x2 is a testing bed
Further readings:
http://www.w3.org/TR/2011/WD-html5-20110525/elements.html#classes