<p>Southwest Airlines is always trying to be funny. Now a case in which its trademark humor apparently failed is turning out to be the funniest story of all.</p>
<p>This week, a judge in Kansas City, Kan., has cleared for takeoff a discrimination lawsuit against the airline. But Southwest's sin is not about overweight or undertall stewardesses, or even about the racial profile of their pilots. Southwest is in trouble over a children's rhyme. And it could cost them nine, ten, a big fat hen.</p>