I'm trying to put a line on this page, http://24.37.102.253:8082/bubbledesign/ , in such a way that it vertically joins all the bubbles (the circles). But for the life of me I can't get it working perfectly. I tried inserting tables with some CSS styles above and below the bubbles but even if I make the table's height 100% it doesn't make the line connect the bubbles. A background picture for the cells didn't work either.

Any ideas?