[jQuery] Replace element by another

[jQuery] Replace element by another


Hi,
I'm a beginner with jQuery.
I know how to switch from an element "a" to another "b", but i can't
find a way to "re-switch" from "b" to "a".
here is my script :
$('a').click(function() {
     $(this).replaceWith('b');
});
Any suggestions ?