So, #testdiv is invisible?
Could you use a getElementsByClassName("testcase-ok") to grab your testcase rows?
with id testcase-ok
You meant class, right?
Then you could use any number of ways to add those tr's to the other table... you could loop through them (since after gettingElementsByClassName you'll have a nodeList, a group of elements) and appendChild to the table (or the tbody if your table explicitly has one). Or, I recently learned, you can createDocumentFragment, stuff the tr's into that, and do one appendChild to the other table.
If you want these rows to move from an invisible table over to another table when the user does something via the browser then go ahead and hit the little flag under your name and in the message box, as a moderator to move this thread over to the correct section. I know this isn't an HTML/CSS question, you can't do this without scripting that I know of.