[jQuery] :contains - a bit more specific?

[jQuery] :contains - a bit more specific?


I have some layers, each of this layers has a span tag with a
username. Now, I want to append some code to each layer that has a
span which contains 'test'.
The code I tried is:
$("div.commentfooter[span:contains('test')]").append('class');
But that also appends 'class' to layers that have a span tag
containing 'testman' or 'tester'.
What do I need to change to only select those layers that have a span
tag that contains the word 'test' and only this word?
$("div.commentfooter[span:is('test')]").append('class');
doesn't work. :-(
---dominik