Help please, with dishwasher repair.

[wurm]

Thanks, all. I just checked the Sears partsdirect site and found an exploded view. It looks like it's the part numbered 15 in this view http://tinyurl.com/dhqsun, but I can't tell from the picture where it should go. At $16.21 and being called a Tab, Sump, I'm getting a sense that it's kind of important. I'd love to be convinced otherwise, though.