Tab like structure in CSS with rounded corners

[semiflame]

I have a CSS rectangle that has rounded corners. I would like to add a tab like structure on top of it.This is what I am talking about.http://i.imgur.com/J2h0Ncm.pngI tried making two different elements and adding together with positioning but it doesnot look real(mainly because of shadow)l. Can we make it on CSS on a single element?Thanks in advance!Edit(more details):I have a rectangle with rounded border as follows:\[code\]#mybox{width: 800px;height:400px;border:thin;border-radius: 10px;-webkit-border-radius: 10px;-moz-border-radius: 10px; border-color:black;box-shadow: 3px 3px 10px 5px #000; }\[/code\]I want to tweak/stretch the top part to look like this.