[jQuery] How to select by id where the id contains a dot?

[Derek Alexander]

Unless I'm mistaken, JQuery (1.2.1) doesn't appear to be able to select by id 
where the id contains a dot.

e.g.

<span id="error.password"></span>

...

// the following does nothing
$("#error.password").append('Required field');



Is this correct, is there any workaround?

Cheers,
D.