I myself have experienced such a case to make me stress, and finally to the efforts and hard work, I found a software / freeware, called CSS Tab Designer.
I have to say that I was pleasantly surprised with the interface of this program. Pretty nice and easy to use, and the most important thing, it generates strict xhtml compliant code. That means you can be sure that your web site will be seen in any browser in the same way.
Another important feature is that you can edit the generated code to customize some properties when needed. Only one features is not present in the interface, you can’t make sub menus, which is a pity and sometimes needed, but you can make similar sub menus based on the original without too much effort.
You can Download CSS Tab for Web Designer here: