Vertical align text in floating div using css

Do you know how to vertically align a text in a floating div? When a content is dynamically generated and you want to align it automatically according to it?

Today i was experimenting about this for a long time and finally i have got a solution which will work in all the browsers including ie6. There are many ways of doing it, but i would like to work the code in all the majore browsers inculding ie6.

So here is the code...

HTML:

It works! Vertically Center Align!

CSS:
.contentdiv{ width: 135px; height: 84px; display: table; border:2px solid red;}
.contentdiv p{ display: table-cell; vertical-align: middle; text-align: center;}

Hack for ie:
.contentdiv p{*margin-top: expression(this.offsetHeight < this.parentNode.offsetHeight ? parseInt((this.parentNode.offsetHeight - this.offsetHeight) / 2) + "px" : "0");}

Hack for ie7:
*+ html .contentdiv{}

Hack for ie6:
* html .contentdiv{}

According to the height you increase, the content will get vertically aligned center. My only worry is iam using expression. We must try to avoid using more expression. But it looks very simple. Fine, any other method of handle this will be a great help! Please feel free to post.