jQuery CSS: Dynamically change attributes of a class

Question

I want to change the attribute of a class on which all element that use the class for the rest of the web application life (from start of use until the user exits the web ap

Answer 1

In addition to what have been said, I think it would be useless to modify a css rule because the already existing elements wouldn't be modified.

I am here 

Now, if you modify somehow the class "myclass" itselef, it wouldn't affect "I am here", because it is not dynamically binded. Perhaps it would affect the newly created elements.